102 thoughts on “Comcast Xfinity Port 25 Blocked, Change to 587 For Outgoing Email (SMTP)

  1. Made the changes to Outlook 2003 per instructions.
    Test message worked OK but could not send outgoing email.
    Eventuall found the info to use port 587 with SSL encryption ‘unchecked’.
    This was a solution that did not require calling Comcast/Xfinity.

  2. I don’t know if my issues are related to this, but I can’t get Comcast Outlook to recognize my user and password, so it errors out. Just started out of the blue yesterday afternoon. Very frustrating.

  3. Thank you very much. Outgoing email just stopped working for us in the Seattle area a few days ago. Port 587 works perfectly. I don’t recall any communication from Comcast about this, but I never look at their newsletters anyway, so I probably deleted it. Thank you EVER SO MUCH for this page.

  4. I, too, don’t recall seeing the email from Comcast about discontinuing use of port 25 for outbound mail. Yesterday, my Outlook 2003 home email abruptly stopped sending. I made the port settings as recommended, and outgoing email is now working again, but my AVAST! antivirus mail scanner is telling me it doesn’t like the SSL connection because it can’t check incoming mail for viruses. I guess I need to contact AVAST! to find out what to do.

  5. I never received an e-mail from Comcast about this issue. I am running Outlook XP at home, and spent the better part of yesterday troubleshooting this issue with tips found on various blogs. One tip was to change my e-mail password, which I tried, but to no avail.

    Today, I continued my troubleshooting, and I am VERY glad I happened to stumble on this message board. I changed my outgoing server port settings from 25 to 465 and it didn’t work. Tried changing to 587, then clicked the “Outgoing Server” tab, checked “My outgoing server requires authentication” and entered my username and password, and it FINALLY worked.

  6. any fixes for this on an iPhone 4S? my 3GS worked fine with sending AND receiving. now I can’t send emails. help?

  7. Thank you for this page! My messages were stuck in my Outbox starting today. You saved me valuable time since I didn’t have to call Comcast support and wait on hold on a Friday night! :)

  8. I have two identicle laptops both running outlook 2003 – both stopped allowing e-mails to go out – have set both computers to ports to 110 outgoing and 587 incoming – with SSL uncecked on both – one works and the 2nd one doesnt. On the laptop that doesnt work it is saying I need to check the e-mail address – any ideas?

  9. Comcast is my ISP and I use Outlook 2007 to get and send email on several addresses. Email would not send for two days. I assumed Comcast had changed something, but dreaded the idea of calling them and talking with someone in India that thinks I’m an idiot. Since it didn’t fix itself, I found your blog and changed to Port 587. Works great now! Thanks. I’m 65 and pretty proud of myself for correcting this.

  10. Richard, Bob, Frieda, Debra and Kim – Glad we could help and that you’re finally able to send email again!

    Annie, sorry I haven’t heard about this being an issue on the iPhone (I too have a 4S). I did locate where your port settings are on the iPhone, but mine were grayed out so I couldn’t edit them (maybe because it’s Gmail), but for what it’s worth:

    Rob, did you also check the box for “My outgoing server (SMTP) requires authentication” on both machines?

  11. I did select that the outgoing server (SMTP) requires authentication on both machines

  12. THANK YOU!! The Comcast IT person told me to use 465 for the outgoing server and it did not work. 587 works like a charm. The Comcast person then told me is must be a Microsoft problem and to contact them. Imagine how productive a call to them would have been. I wound up calling Comcast back and training their IT person. (Another rep told me to use 465 only when traveling).

  13. I have tried 465 and 587 – just started yesterday in Nashville – neither one is working – any ideas ? I download emails from my business site to my Outlook which is managed through Comcast – so I can receive but not send :( AND by the way – I never received ANY email on this – I googled and found this – so thank you ! Any other ideas ?

  14. Hi Sarah,

    The box for “My outgoing server (SMTP) requires authentication”?

    Maybe also try checking/unchecking “This server requires a secure connection (SSL)”

    Alternatively you can follow the links to Comcast’s own instructions above which also include changes to incoming server, but I wouldn’t think that should be impacting anything (especially given that you, like most everyone else, are still able to receive).

    Otherwise, I’m afraid I don’t know what the issue could be – sorry. You’ll probably want to call Comcast or talk to your company’s IT person.

  15. i have an e-mail provider that is different than comcast. so i want to keep my incoming server and change to the comcast outgoing server. no luck. can’t get outgoing e-mail to send but can get incoming e-mails…

  16. I have tried the following combination on the ports 995/465 & 995/587 and both don’t work on my end. I have outlook 2010. I have been on the phone with comcast (US, Mexico & the Philippines) – nobody was able to solve the problem. They told me to call Microsoft. Any solution?

    Thank you.

  17. First off, thank you!! Just knowing there is hope gives me some relief. I haven’t been able to send email for 3 days, but I don’t see my exact problem here and I need specialized help. I don’t RECEIVE my email through Comcast, I only SEND it, so I don’t want to change any of my incoming email settings. I have Outlook 2007 and have changed my outgoing settings to 587 and SSL, to no avail: I still can’t send email. :( Do you have any other ideas for me to try, or am I out of luck?

  18. Just noticed this today. Outgoing Emails for the last two days were hung up in my Outlook 2010 outbox.

    I use another service in Outlook for incoming POP3 mail. I don’t use a comcast.net account for that purpose. I think many comcast customers do the same.

    So the instructions on Comcast’s website and in your screenshots are incorrect for users with non-Comcast pop3 accounts. I that’s the case, you do NOT want to check: “Confirm that Use same settings as my incoming mail server is selected.” Instead, configure the smtp account separately.

  19. I made all the changes that Comcast requested incoming server to 995 and outgoing to 465, the problem I’m having is that I’m not receiving e-mail on my laptop or on my wifes Samsung 4G phone, I am getting all my e-mail on my home computor at least I think I am. I was getting mail the other day on my laptop (Fri.)but nothing was received over the weekend even though we got about 15 e-mails on the home comp. My wifes phone may get 1 or 2 mails a day but then they delete themselves an hour later.
    Also when I log onto Comcast web site to check my mail ther is nothing there either, everything has been deleted mail that has been there for months, it is however receiving spam, I checked the folder and there’s spam sent every day. Any ideas on this one? all settings are set the same on all comps. and phone. Comcast has no idea (lots of help they are)Any help or direction would be appreciated

  20. I am sorry to bother you. However, I have no one to turn to. I use a POP3 acct to download messages to my Outlook 2007 and the Comcast SMPT to send messages from the same acct. Like most everyone else, my incoming email has not been affected: it’s the outgoing email that no longer works. I cannot reconfigure my “Incoming” settings as this will render my email completely useless (and right now, at least I can RECEIVE email.) Changing the “Outgoing” settings as described above has not helped, even after 1) restarting my computer, AND 2) resetting my router.

    I cannot log onto Comcast and get tech help through their forums as I am merely a renter in my home and my landlords live out of state (and have the acct number/password/etc) and I just merely utilize the Comcast internet services provided to this address.

    Is my only choice to quit using Comcast now and set up a gmail, yahoo, or other type of outside email acct? :( I hate to give my email address I have used for 15 years!! :(

  21. Sorry Bruce, this is a separate issue and one I’m not that familiar with. I suspect it has something to do with messages being downloaded off of the server. Once they’re downloaded to your home computer, they aren’t available for download on any of your other devices or in webmail. There is an option in your account settings to “leave a copy on server”, but I haven’t personally played around with it.

  22. Hi Melanie,

    Sorry to hear about the trouble. You shouldn’t *have* to give up your email address, although I would recommend considering it at some point so there isn’t a risk of something like this. (Personally I switched to Gmail years ago, because I wasn’t certain Comcast would always be my ISP). That said, if you’re using a comcast.net email address (as your message indicates, but not your author info in this comment), some variation of the instructions above should be working. If for some reason I’ve misunderstand and you’re not using a comcast.net email address, give Carl’s instructions a shot and let me know how it goes. Sorry I couldn’t be of more help – the 587 outgoing port change seems to do the trick for most.

  23. I have been dealing with this all morning and just got it to work……
    key is: pop 3
    Settings: incoming outgoing same
    check requires log in auth.
    More Settings: (check requires auth.)
    advanced tab: Incoming 995 requires auth.
    Outgoing (SMTP)465 Encrypted connection SSL

  24. Hi Randy! Thank you so much for responding!! I called Comcast Security Assurance at 888-565-4329, spoke to a rep and got everything straightened out!

    Carl is correct: for people who use a different POP3 for INCOMING mail, do NOT check the “Incoming is the same as outgoing,” because really, they are NOT the same.

    The whole issue here is that now the OUTGOING SMPT server requires authentication, and the only way to get it is to have a Comcast email acct to verify the information against. I don’t have a Comcast email address, I only use the Comcast “broadband” that comes into my house to send/receive my messages. The box that must now be checked is “My Outgoing Server Requires Authentication” and then “Log On Using (enter User Name and Password).” Since I don’t have a Comcast email address, my landlord let me use her username and password (the other option was for her to call or go online and set up a new Comcast email username and password under her acct at no charge.) Be sure to check “remember password” so you don’t have to do it everytime you want to send an email! :)

    The rest of the instructions are correct: Outgoing = 587 and then “Use the following type of encryption” = None.

    And now I’m back in business!!

    I hope everyone gets everything straightened out and can be up and running soon! Good luck!! If all else fails, the 888 rep was very nice, informed and supportive!

    Thanks again!

  25. Ditto to the post below. Same notice, same problem, and same solution, execpt I am running Outlook 2007.

    8. Debra Dupree says:

    February 26, 2013 at 3:42 pm

    I never received an e-mail from Comcast about this issue. I am running Outlook XP at home, and spent the better part of yesterday troubleshooting this issue with tips found on various blogs. One tip was to change my e-mail password, which I tried, but to no avail.

    Today, I continued my troubleshooting, and I am VERY glad I happened to stumble on this message board. I changed my outgoing server port settings from 25 to 465 and it didn’t work. Tried changing to 587, then clicked the “Outgoing Server” tab, checked “My outgoing server requires authentication” and entered my username and password, and it FINALLY worked

  26. I started having problems in Feb 2013 when I ntoiced my e-mail program would not connect to the outgoing server. Incoming mail was still working. The outgoing mailwas getting redirected to smtp.g.comcast.net and then timimg out.

    My bigger problem was that I was (deliberately) using an old version of Eudora (3.05 Professional). I’ve beeen using this since I first got on the ‘net in 1999 and suince March 2004 when Comcast broadband was first offered in my area. The problem was this version of Eudoora could ONLY use port 25 for outgoing mail and could NOT be changed.

    I changed to the last version of Eudora ( but I could still not get it to work. Googling on the net lead to dozens of posts of Comcast users that could not get Eudora 7 to work. Eudora is no longer being developed and Comcast ofefers no help or support at all once they find out you are using this e-mail client.

    After about a week, I finally got everything working by trying every combination of options and settings. I still could not get port 995 to work for incoming mail at all on either Thunderbird or any version of Eudora. Port 110 works for both. I have to use pop3.comcast.net for the incoming mail serrver as mail.comcast.net does not work at all with either Thunderbird or Eudora no matter what options I set.

    For outgoing mail, port 465 would not work withe either Thunderbird orr any version of Eudora, but port 587 does works for both.

    With Eudora I have the ‘use authentication’ box checked. With Thunderbird if I use either STARTTLS or SSL for the autherntication I get a huge warning message about Comcast’s certificate being invalid. The only way I can continue is to accept the security exception (and it says valid public sites will not ask you to do this). If I deselect the STARTTLS or SSL option and just use no autentication the error messgae does not appear.

  27. The port 25 issue finally hit our house today. No email sending, but receiving from port 110 still worked. We have Outlook 2007 and use comcast email addresses exclusively on this client. We tried the solutions noted in the two links on the comcast website and they didn’t work. We tried port 587 with encryption set to “none” and that did not work. I was on Chat with comcast for an hour and they gave up. BTW, my Outgoing Server tab has a check on the “My outgoing server (SMTP) requires authentication” and a check on “Use same settings as my incoming mail server”. I am using port 110 for incoming mail and that works fine.

    Any advice would be helpful. Thanks.

  28. Just encountered this problem last night. Googling around I found this site and your instructions worked perfectly(using 587 not 465). Comcast wanted to charge me over $50 to give me this info! Thank you, thank you!

  29. Sorry Jeff, it sounds like the problem you’re having may be the result of something different, if you’ve tried everything we’ve talked about here (including suggestions from other commenters). I guess at this point you’ll want to call Comcast.

  30. Comcast vs Outlook 2010 – I won’t go into my brain splitting frustration talking to folks all over the world who didn’t get it and we couldn’t understand each other and then being disconnected tons and then them trying to sell me a service plan. Don’t buy any of that crap. I finally got a direct line in North America Call 1-855-704-4217. But you don’t have to. I figured out my problem. It was helpful to read what Randy said but I was still having problems. I read a post from Denis B. about Avast which gave me another idea. Some of the connection errors I got had to do with encryption. Some were using SSL, sometimes None. I did some tests and nothing helped. Then I shut down my avast temporarily and was able to send a message. When I went back into my outlook settings I noticed that the encryption connection had automatically changed to TLS. I knew then it was Avast blocking me. I went to avast/antivirus/mailshield (be sure your window is reduced sometimes the buttons are hidden if you don’t)and clicked on settings.In settings click on SSL Scanning. I changed the protocal on the SMTP for comcast that said 25 to 587 then made sure the encrption was set at TLS and clicked ok. It didn’t work the first time so I unchecked the box in the top that says “Scan SSL Connections” and it worked. I then tested it again with the “Scan SSL Connections” checked as I didn’t want to turn that off, and it worked perfectly. It is hinkey to get all the settings to stick but it works. Hope this helps you. I changed my cell phone services, cable service and a few other, all at the same time and just about lost my mind.

  31. I’ve also been unable to send mail on Comcast accounts since March 6 and Comcast has been unable to resolve the issue, until today. The problem was the same on two separate computers with different operating systems and e-mail clients as well as on two iPhones and all stopped working at the same time. I had tried all combinations of ports 465 and 587, with and without SSL, to no avail. Eventually, Comcast referred the matter to a “Security” technician who suggested that my modem/router’s firewall might be blocking those ports. Sure enough, after I added an exception for port 465 in the firewall settings, everything worked. The phones were misleading as I had only tested them at home, where they were connected by wi-fi via the router (Motorola SBG900). Perhaps this will help others.

  32. The Port 25 problem hit me today. I’m currently using an old Version of Eudora (4.2) but receiving all mail ok.
    I just can’t send. I changed the Port to 587, but this did not fix the problem. I called Comcast and they have not yet fixed it. I think all it wants is to authenicate a password but I don’t know how to fix that. Any help would be appreciated.

  33. Thanks so much for this, I suddenly ran into the same problem after experiencing a recent power outage and losing my Comcast IP for an hour. On restart I suddenly couldn’t send email anymore; receiving was fine. I knew the issue had to be Comcast because when I connected with my backup 4G hotspot, the outgoing emails went immediately.

    After three days of tinkering, I finally found this. 587 gave me a certificate pop-up on its first try; I passed through that and now everything’s fine. I do have the “use same settings as incoming server” ticked, btw, and everything’s fine. This a for non-Comcast POP account.

    Thanks again!

  34. Why does Comcast not think their customers are smart enough to use TLS over port 25 for authentication? This is a poor excuse to drive users to Comcast’s data-mining mail servers. I’m away on business and had important emails from my family blocked. RESPECT PEOPLE’S RIGHT TO UNFILTERED INTERNET TRAFFIC.

  35. What is the problem with Comcast, I know it’s not my problem and trying to get help from them is horrific for all people.. I am JUST SO MAD FOR WASTING MY TIME to fix their screw up with this port migration problem.. Comcast is a horrible company to deal with, what everyone of you should do is take your money and go to their competitors and let them loose money.. Yes I just have a very bad service from them.. Why should I have no ability to send out my e-mails because spammers are using their network and they are too stupid stop them, well my money is going elsewhere NOW, I had enough of their crappy service, enough is enough, Al.. My e-mail is geoexpl@yahoo.com

  36. Richard, would you show or tell how you made this setting change on the Motorola SBG900? You said “added an exception for port 465 in the firewall settings connected by wi-fi via the router (Motorola SBG900)”. I would be thankfulfor help on the Comcast port change issue.

  37. VERY glad to have found this site after two days of troubleshooting. I used Outlook 2010 to manage a Hotmail account as well as a business (non @comcast.net) address with Comcast as my ISP. Suddenly, I could no longer send out email on the business account through Outlook.

    Thanks to Carl and Melanie’s posts above, PROBLEM SOLVED!

    I had to change my outgoing mail server to smtp.comcast.net and input our COMCAST account username & password information for the outgoing server authentication login. Luckily, my husband had record somewhere of the Comcast username (technically a comcast email address) and password associated with our service.

    Good luck to all!

  38. I appreciate all the information everyone has given on this website. I am in Illinois. My emails stopped sending out. I thought I did something. Realize Comcast did it. Yes, I called them and they wanted me to pay $54 for subscription and enrollment fee to get help from their techs. They caused the problem abd I should’nt have been asked to pay for their techs to solve it. I use Outlook Express for email, which isn’t a comcast product. I went to tools, Accounts, Mail, Properties,then Servers and had to mark that my outgoing mail server requires authentication. Then went to “Settings” on same Servers Tab and marked “Log using, Account Name (my email address), Password, and checked “Remember Password”. Then went to tab “Advanced” and changed to Outgoing Mail port #465 (587 didn’t work). and then checked This server requires a secure connection (SSL). I left incoming POP3 at 110 and left “this server requires a secure connection(SSL)blank also. Applied, and ok’d each screen. Logged out and back in email and now my emails are going out. :)

  39. Roy, I had the same issue and have the SBG900. It blocks port 25 by default. Go into the router settings, Click on the firewall link and in Basic Policy select Custom and click Apply. Then go to Advanced Policy page. Go to the bottom and select the type of policy you want to copy from. I selected Medium. Then click the apply button on the very bottom. Scroll up to the SMTP Port ID line and click the right most button on that row to delete the policy (set to 25:25 range). Click the first Apply button on the bottom. Then at the top, add the SMTP policy, click Enable, enter the port range of 587:587, use TCP, then click the allow Outbound. Click the Apply button on the bottom (not the very bottom – be careful). Then logout. Change your mail settings and you should be good to go.

  40. Jeff,thanks for the info. I did find this and figured it out exactly as you outlined and it worked great. I could not get mail from my iPad for a year on my Comcast wireless due to the port settings on the Comcast e-mail defult and called the Comcast help and they could not figure it out and wanted me to buy their support services. While working to fix the port 25 change, I finally figured out that it was the same problem, the firewall settings on the SBG900. Glad I found this site.

  41. I finally got my copy of Eudora 7.0.1 working with the new Comcast authentication protocol. Here are the settings I used:

    Under Tools:Personalities
    – Configure your “Dominant” persona “Properties” to use your Comcast email account. Use your Comcast Email addy & Username. The smtp server is smtp.comcast.net, Check the next three boxes: Allow Authentication, Relay and Use Submission Port. In the “Secure Sockets when Sending” pull down select “If available Start StartTLS”

    – Configure each of your other personas (meaning your other email accounts) so that the “Use Relay if Defined box” is checked.

    Under Tools:Options:SendingMail tab, set the “SMTP Relay Personality” to “Dominant” You should also see the: Allow Authentication & Use Submission Port boxes checked. The “Secure Sockets when Sending” pull down should say “If available Start StartTLS”

    Those settings will make all your non-Comcast accounts use the Dominant account settings to send email out. Only trick left is to get Eudora to authenticate an outgoing message with your Comcast username/pwd. I say that’s a trick because I’m not entirely sure what I did to make that happen. After a few hundred experiments, it just came up and from then on I could send email again. Here’s what I think worked.

    Tools:Options:Checking Mail
    – Mailserver should be pop3.comcast.net
    – Username should be your Comcast username
    – Save Password should be UNCHECKED

    Now, compose a new outgoing message from your Comcast account. When you try to send it you should be asked for your password. Enter it and if it works, you’re a lucky dawg. Go back to Tools:Options:Checking Mail and check the Save Password box. Send another msg and this time the password will be saved.

    I apologize if that last bit sounds like black magic. If Comcast were anything like a professional organization we wouldn’t have to spend endless frustrating hours trying to fix a problem they intentionally created for their customers. I played with the phone robots and lame tech support group for a couple of hours this morning before I gave up. The end game for Comcast seems to be selling us their “Signature Support” but I guarantee you they wouldn’t have been any help with this. They told me that Eudora was no longer supported and that I needed to upgrade to Outlook.

    Greedy Corporate Louts! Shame on you Comcast.

    FYI, just in case anyone needs it…
    Here’s info on changing ports in Eudora manually although you shouldn’t need it:

  42. I have two NAS devices from different manufacturers. On my Synology DS1512+, I was able to successfully change the SMTP Port for email notifications to 465. However, I am unable to change the Port# for email notifications on my older Buffalo Terastation Live. My Google research tells me that Port 25 is hardcoded into the firmware on the TSLive.

    Is there anyway to change the outgoing port via my router? My router is a Netgear R6300. Any other suggestions are welcome.

    A light finally went on after reading Kara’s email…
    FOR NON comcast.net users:
    1. In Internet Email Settings – Change the outgoing email (SMTP) to smtp.comcast.net
    2. In More Settings/Outgoing Server – check the box “My outgoing server requires…” AND choose “Log on using” the username and password you use to log onto the comcast.net website. Check Remember password. This username and password is different than the one I used on the Internet Email Settings page.
    3. Under the Advanced tab, use 110 for the incoming box and 587 for the outgoing box. You might have to try both ways as to whether your server requires encryption.

  44. Thanks to ALL. This morning, a Comcast truck was at the pedestal outside our house. Suddenly ~ whammo, not able to send on Entourage for 5 of my 6 accounts (don’t ask). Or my iPhone 4s. Same bullshit from Comcast: the initial CSR said she can’t troubleshoot third party email clients. I tried to explain I tested it all at two restaurants today, and on 3G on the phone WITH NO PROBLEM, meaning it was on Comcast’s end. She shuttles me to “Signature Support” who immediately begins trying to sell me by painstakingly listing the “benefits” of the service … I finally had to ask her to cut to the chase and the $, which would be $39,95 set-up and $14.95/mo. Amazing! I’ve been using the service for 13 years with no issue, and suddenly the ONLY place it doesn’t work is in my home and they want to charge me. THANK GOODNESS for forums ~ found the solution in about 10 minutes. LESSON LEARNED ~ check w/the people first!

    Now, I’m off to social media to lambast Comcast. I suggest others who were given poor customer service do the same.

  45. Still having comcast outgoing mail issues,will not send. I have tried changing the port to 587, still not working.

    I have a dell laptop running windows 7 with outlook 2007.

    I receive mail fine, but can not send email, however I have been able to send email off and on, without changing settings.

    Also- recently had a comcast email address all of a sudden start receiving a ton of spam type emails when I wasn’t before.

    If anyone can be of assistance I would be very grateful.

    Frustrated – Jenn

  46. I am having the same issues for out going mail, however, the only problem is through a scanner for “scan to email.” Incoming and outgoing email traffic is through gmail, but the scanner is on a comcast network. What do I need to configure for the scanner to work? I do not have a comcast email account. Thanks so much!!!

  47. I am using Outlook 2003 as my email client. I have two pop3 accounts. A xxxxx@msn.com one, and a xxxxx@mr2cents.com that is hosted by ipower. The @msn account I have set up with incoming port 995, out going set to 587 works perfect with “this server requires ssl connection” checked off for incoming and out going mail.

    On my xxxxx@mr2cents account if I check off “this server requires ssl connection” no matter what ports I am set to, I keep getting a warning error:

    “The server you are connected to is using a security certificate that could not be verified.

    The certificate’s CN name does not match the passed value.

    Do you want to continue using this server?”

    I click yes and everything is fine. This warning comes up every time I open Outlook 2003.

    Now, if I do not check off “this server requires ssl connection” then the xxxxx@mr2cents works fine. No error message, when I start Outlook 2003.

    I trying to find out, if I am playing with fire by not checking off the “this server requires ssl connection” boxes. But again this is the only way I am able to get rid of the warning, CN name does not match the passed value.


  48. Forgot to mention that my email problems started on 3-13-13
    out of the blue nothing would leave my out box.


  49. Please since again comcast changed their ports my outlook 2007 has been resolved. However, my husband uses gmail & the info I was given was type:pop incoming: pop.gmail.com outgoing: smtp.gmailcom incoming port:995 outgoing port 465 ssl should be turned on. Still no emails are going out. I called Microsoft they will not help me unless I pay them $100 bucks for 30 days. I also tried the port 587. He gets emails in but no emails go out.

  50. Please can anybody help. My outlook out going emails with comcast have been resolved. However, my husband uses gmail & his out going emails on outlook 2007 are not going out. His setting type: pop incoming: pop.gmail.com outgoing: smtp.gmail.com incoming port 995 outgoing port 465 ssl turned on. Still no outgoing emails. Microsoft will not help unless I pay them $100! Comcast tells me it is a Microsoft issue. I have been on line for hours trying to resolve this issue.

  51. They’ve stepped it up. Now Comcast has made this change on their business class customers and has taken at least one of my customers Exchange servers offline. After talking with Microsoft (who was not happy with this change)and working with Microsoft on making the appropriate changes, emails STILL are not going out or coming in.
    The ports that they told us to use were 465 for incoming and 587 for sending. After ANOTHER call to another technician, he tried to give me a different port entirely. I don’t think Comcast has the slightest idea what they are doing.

  52. Outlook wasn’t working with Comcast either. Incoming mail worked fine. Outgoing did not. Changed incoming server to 995 and outgoing server to 587. I also had to put in my email user and password to re-set configuration. File save changes. Now working. This is Comcastic!


  53. I didn’t realize my emails weren’t going out for a few days. Spent hours trying to make all the suggested changes. Finally fixed it with the following post. Thanks Bill!

    Bill Draper says:

    March 11, 2013 at 3:10 pm

    I have been dealing with this all morning and just got it to work……
    key is: pop 3
    Settings: incoming outgoing same
    check requires log in auth.
    More Settings: (check requires auth.)
    advanced tab: Incoming 995 requires auth.
    Outgoing (SMTP)465 Encrypted connection SSL

  54. I lost the ability to send email Saturday 3/30/31.
    I followed Comcast’s recommendation for Outlook 2002 (2003) exactly to change the ports to 995 and 465. That only made it worse. Now I can’t receive emails. If I leave it at 110, no SSL I can at least recieve email. I tried your suggestion of using port 587 to send. That didn’t work. I installed Thunderbird. I set it up exactly like Comcast recommends (995 and 465). I can’t send or recieve. I tried ports 110 and 587. Now I can receive, but still can’t send. (BTW (I spent over 90 minutes on the phone with Comcast. I spoke to 7-8 different people (same story as above with them promoting their signature service…) I verified with each that I had each config screen set up as they wanted. It doesn’t work.

  55. Looks like Comcast finally got around to blocking port 25 on my home internet connection on April 1, 2013. I run my own Exchange 2010 server, and suddenly couldn’t send or receive e-mail (my volume is incredibly small–a handful sent and less than 100 received per day, average 80% spam).

    I’ve successfully configured my firewall and the Exchange Send and Receive Connectors to support port 587, and then configured an SMTP Port Forwarding service (EasyDNS.com) to relay my mail via port 587. Mail’s flowing again.

    Interesting that it took them so long to finally block the port in my area.

    David Marcus
    Frederick, MD

  56. I have same issue – unable to send email but able to receive it. It stopped working suddenly.

    I tried all the options as mentioned but no luck.

    But it is working normally when I tested it at my friends house.

  57. Sorry to hear that Reddy. The only thing I can recommend is trying various combinations of the instructions above and note the different settings that should be used by comcast.net users vs. others.

  58. Your tips were clear and easy to follow, but I cannot send or receive. I have checked my set up numerous times to no avail. Any ideas?

  59. Well….
    something was changed
    using 529 for a while, now that doesn’t work

    may cancel service and go with a hot spot AT&T

  60. I have spent the last 2 days dealing with the most inept Comcast techs. My incoming email stopped suddenly. It’s been working fine all along (years). Several people have told me they sent emails, one especially a hotel confirmation, was never received. To get around this issue for now, I had all mail forwarded to my gmail account. The techs had me uninstall and reinstall Chrome, “that will work.” No it didn’t. Now I know why I’ll never have any bills sent email……….just won’t get them. What do I do short of changing from Comcast to something else?????
    Thanks for your replies and assistance.

  61. Both POP3 995 and SMTP 465 ports work for me when using Outlook and Comcast mail. I tested both incoming and outgoing. Make sure you have both the boxes checked for incoming and outgoing mail: “This Server Requires an Encrypted Connection (SSL)” in Outlook when changing to 995 and 465 ports as it won’t work and you won’t be able to send/receive mail if you don’t have these boxes checked.

  62. Randy, you are a genius! Thanks so much! I have been looking for a fix for a couple weeks now, and this saved me from throwing my computer out the window. Love me some Comcast…

  63. I may have a more complicated issue here. I am running Outlook 2010 with my hotmail account as my default account and Comcast is my ISP. I do not have the option of changing my port setting for this account only! I have two others on there and they are both set to send from port 587 and working fine. The hotmail account is receiving fine but, it will not send. Any ideas how I can change that port setting? I also am using the hotmail connector which I think may be part of the issue. Thanks!

  64. My scan to email function on my HP Color Laser Jet CM2320fxi MFP quit working in January, and I am getting around to fixing it. I use Outlook 2010, but do not have any issues getting or receiving email from Rackspace; only the outgoing email from the scanner is affected. With Port 25, the scanner said that it “cannot connect to the SMTP server.” After verifying the SMTP Gateway for Comcast (my carrier), which is smtp.comcast.net, I changed the SMTP Port to Port 587. Now, the scanner says the “an error occured while sending the email. Try sending again.” Repeating the scan did not work. I think the issue must be with the HP scanner, but HP business customer support (apparently the only one qualified to advise on scanners) is only open M-F. Any ideas gladly entertained!

  65. David Marcus

    I have no isea how to setup an SMTP Port Forwarding service (EasyDNS.com) to relay my mail via port 587.

    can you help me with that, please

  66. I also have all of a sudden stopped recieving email on outlook 2007 on 2 of 3 computers. Comcast just told me you can only use outlook for 1 computer this makes no sense. So I changed the settings to the setting on the one that does work and it stops again. I find this a little hard to believe after 7 years of using outlook on 3 computers it does not work anymore

  67. Judith, if you want to receive all messages on multiple devices, you should set up your account as IMAP rather POP. Alternatively, you might be able to get by checking the box for “Leave a copy on the server” in your advanced settings, although in your situation that’s a workaround that may not produce ideal results.

  68. Using Outlook 2010, outgoing emails stopped working a few days ago. port 587 no SSL and auth. req. still does not work. Any ideas? Thanks.

  69. Thank you a thousand times thank you.
    I was more than an hour and a half today with a Comcast
    “technician” who did not tell me about the blockage of Port 25 and could not fix the problem of my outgoing mails, I have another server for my incoming mails and Comcast for the outgoing.
    This “advice” was given after accepting to pay 49,95 dollars for a one time advice and solution (which was not the case) we are now hoping to get a refund. The tecnician blamed my incoming server. Reading your advice I could fix the problem and it is working perfectly!

  70. Glad to help Ines. Comcast really screwed up here – as you can see I wrote that post several months ago but the problem is still cropping up newly for customers all the time.

  71. I too have just experienced the “send” outage!
    After trying every combo of settings and hours of calls and offers to fix the problem for hundreds of dollars, I finally can send emails with my Pop3.
    110 in
    587 out, no SSL
    Requires authentication
    Put in your Comcast user name
    And your Comcast password
    Not your Pop3 password

    And like magic I’m back in business !!
    Good luck and thanks for all of your good posts and advice.

  72. I am a Comcast e-mail user through comcast not thru outlook or anything else. I can send e-mail but not receive. I spoke to a Comcast rep and she stated that my incoming ports 25 & 587 were blocked (not by me) and I needed to change my ports to 995 (?) and 110(?). However she did not know how to direct me to do it!

    What is really interesting is that my wife’s email account is on the same computer and she goes straight to Comcast e-mail and doesn’t have a problem.

    Can someone please explain in how to accomplish this!

    Since I can’t receive email at comcast I have left an alternate email.


  73. Yes. I check my email through Comcast. I have other email accounts such as yahoo and hotmail. Again I go directly to those accounts. I do not use an email client.

    My wife accesses her emails in the same way. we also use the same computer with IE 9. She has no problems, so I don’t understand why I would need to change ports

  74. Sorry to hear about the trouble Tom, but unfortunately this is a completely separate and unrelated issue. And it sounds like the Comcast person you spoke to was clueless. Port settings shouldn’t be an issue if you’re simply using web mail. The issue we’re talking about here with outgoing ports is the result of Comcast changing which outgoing ports it supports for those that use an email client.

  75. Sorry,

    When I saw the discussion about ports I was hoping to gain some knowledge and maybe solve my problem.


  76. I too have just experienced this problem. It worked fine before I went on vacation and figured I had “gremlins” invade the computer while I was gone. I have tried everything (I think) that ppl have mentioned and still can’t send (just receive). I am currently set at 110 and 587 … ugh this is annoying!!

  77. Add me to the list. I’m using a Mac and out of nowhere on Wednesday, I am no longer able to send. Calls to Comcast were useless as they say as long as you can use the webmail, the problem isn’t on their end. I have tried changing my ports to 587 and 465 with and without SSL/password and it still doesn’t work.

    Is there something else I can try?

  78. With Outlook 2007 and MSN/Hotmail service, for me the final solution was:


    Account Type: POP3
    Incoming mail server: pop3.live.com
    Outgoing mail server: smtp.live.com


    Check box: “My outgoing server (SMTP) requires authentication”

    Select circle: “Use same settings as my incoming mail server”


    Incoming server: 995

    Check box: “This server requires an encrypted connection (SSL)”

    Outgoing server: 587

    “Use the following type of encrypted connection” – select from drop-down menu: “AUTO”

  79. After much difficulty, days on the phone with the Comcast techs offshore and being charged for extra service I never agreed to pay for, I am able to send and receive from my Mac. Still can only receive email on my iPhone 4s. How do I get it to send email? Like others, I had no problems for years, now Comcast has me irate!

    Is there an easy solution–other than quitting Comcast?

  80. Here’s a work around solution to the email problems. It took me several months to figure out, but it finally worked for me and several others.

    I was using hotmail pop through MS Outlook with Comcast ISP. I could not send email. Tried everything here and all the other forums. Nothing worked until this. I’m posting it everywhere. Why? Good Karma.

    Here’s the work around.

    1. Set up a personal gmail account.
    2. Use their SMTP outgoing server.
    3. On the Outgoing server tab, log on using your gmail account info.
    4. Use outgoing server port 465, require SSL
    5.You’re all set. Now you can send email!

    It’ll take you 2 minutes.

    I don’t know why Hotmail/Microsoft and Comcast are not playing well together, but gmail works great.

    Good luck everyone! I hope this saves you a lot of frustration and lost time.


  81. Thanks so much for the 587 solution without needing to check on SSL.
    Why didn’t I find this answer sooner.


  82. The Alternative Simplified Instructions for Non-Comcast.net Users worked for me. I have been having trouble sending emails from home since I switched to Comcast. I have Comcast at work as well but never have a problem. Not sure if it is because one is commercial and the other is residential but the above solution worked and I am very thankful for everyone that takes the time to give solutions.


  83. For Gary who asks about the ‘Error’ where the Certificate Cannot Be Verified and the Prompt asks if you want to continue using the Certificate.

    The reason for this error should be that Comcast or the email server that you are using is sending a different Security Certificate than you were receiving before you got this so-called ‘Error’. You should be able to reply Yes or No and get the same results which will be that it should allow you to Send/Receive email messages as you did before. I am an AT&T user and this happened to me a while back and I realized what they were doing and called them to notify them that they were sending out an incorrect Security Certificate. AT&T level one support insisted that this was an Outlook problem and I had to contact Connect Tech and pay to have the problem resolved. It took me 45 minutes for me to get level one to transfer me to level two who instantly knew that the problem was on their end and forwarded my notification to the correct area for resolution.

    What the so-called problem was is that the name on the Security Certificate had been changed from the correct email server name used in the Outlook Email Account configuration. I presumed that the server specified in the Security Certificate was something like a test email server. In any event it had all the same email accounts on this other server so what I did was just to change the server names in my email account to match the Security Certificate server name and everything worked again without this ‘Warning’ message. However, the Security Certificate does not list the outgoing email server name so I had to guess what the new email server’s name would be which wasn’t difficult because I just used their naming conventions and applied it to the incoming server name to determine what the outgoing email server name would be.

    In short this should not be a problem other than a nuisance if the same set of circumstances on the Comcast Security Certificate are the same as what mine were.

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