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Tuesday, February 25th, 2025 8:05 PM

SMTP server issues

I have been using the Comcast/Xfinity server for several years with no issues. Today I received an error from my Gmail client that my SMTP is misconfigured. I checked the settings and they are per the Xfinity support FAQ i.e.

smtp.comcast.net port 587

Secured connection using TLS

Username: my_xfinity_username

Password: my_xfinity_password

I checked both username/password was correct by logging onto Xfinity.com

Xfinity uses a single username/password for both Web and SMTP access

I pinged smtp.comcast.net and it returned:

smtp-p.gslb4.comcast.com

but I received an error that the host was uncontactable

I suspect the SMTP server is down. Or there is some username/password validation issue

What say you?   

Expert

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109.1K Messages

17 days ago

Concern moved here to the E-mail help section for assistance.

4 Messages

@EG​ Thank you for your assistance

Expert

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109.1K Messages

@user_w65ydz​ 

Quite welcome !

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer!tick

Expert

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31.3K Messages

17 days ago

@user_w65ydz 

Are you able to log in to webmail?  [https://connect.xfinity.com]

4 Messages

I haven't tried but Webmail is handled differently compared to using an email client that relies on SMTP for outgoing mail

1 Message

16 days ago

This anyone having problems with connection for the outgoing server with your comcast.net email.  I received a drop message and can send any emails. Only receive them.  The port and information is correct.  Any help would be appreciated

4 Messages

Are you able to ping the SMTP server smtp.comcast.net? (from a CMD prompt, ping smtp.comcast.net) I can't so I'm pretty sure that's where my problem is

Official Employee

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1.6K Messages

Hey there, @user_s4gwn6! Thanks for leaving a comment with your shared concerns. You have come to the right place for help! Our Digital Care Team is awesome to work with because we'll always do whatever we can to help review and resolve issues quickly. Are you still experiencing issues sending emails from your Comcast email account? If so, feel free to create a new post so that we can properly address your account, specifically. Thanks!

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

Official Employee

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2.4K Messages

15 days ago

user_w65ydz

Thanks for reaching out! It sounds like you’ve already done some solid troubleshooting, and we appreciate the details. If your SMTP settings are correct and you’ve confirmed your username and password by logging in to Xfinity.com, there are a couple of things we can check next.

 

First, try sending an email from a different email client or device (like a web-based mail app) to see if the issue is isolated to your Gmail client. If the problem persists across different platforms, it could point to an authentication issue or a temporary server issue.

 

Next, double-check that third-party access is enabled in your Xfinity email settings. Sometimes security settings can block SMTP access, especially if there was a recent account update or security patch. you can find the instructions to do so here: https://www.xfinity.com/support/articles/third-party-email-access

 

If you haven’t already, restart your router/modem and temporarily disable any VPNs or firewalls to rule out connectivity issues.

 

If the issue persists, we recommend trying again later or reaching out to Xfinity Support to confirm if there are any known service disruptions in your area. Let us know if anything changes!

Gold Problem Solver

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26.3K Messages

14 days ago

... Webmail is handled differently compared to using an email client that relies on SMTP ...

Yes, it is, but webmail is useful for checking whether a Comcast.net email address and password are working correctly. If the ID and password doesn't work with webmail, they won't work with an email client either.

Are you able to ping the SMTP server smtp.comcast.net? ...

smtp.comcast.net doesn't seem to respond to ping. But you can try:

    telnet smtp.comcast.net 587

        resomta-a2p-646771.sys.comcast.net ESMTP server ready

    help

        This is resomta-c2p-555483.sys.comcast.net ESMTP service help
        end of HELP info

    quit

        resomta-c2p-555483.sys.comcast.net closing connection

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