My mail app gives an authentication error when I set up Xfinity email
Sign in on the Xfinity Email website, open Settings, turn on third-party access, then try the app again.
Xfinity (Comcast) Email: Settings, Sign-In & Fixes
Comcast runs @comcast.net email under the Xfinity name. A mail app will not connect until you turn on third-party access in the Xfinity Email website settings, even with the right password.
Covers @comcast.net. Run by Comcast (Xfinity). Checked against Xfinity (Comcast)'s own help pages, November 2026.
Xfinity (Comcast) email server settings
| Server | Address | Port | Security |
|---|---|---|---|
| Incoming (IMAP) | imap.comcast.net | 993 | SSL/TLS |
| Incoming (POP) | pop3.comcast.net | 995 | SSL/TLS |
| Outgoing (SMTP) | smtp.comcast.net | 587 | STARTTLS |
- Username: Your full comcast.net email address (sending uses your Xfinity ID and password)
- Password: No app password, but you must allow third-party access in the Xfinity Email website settings before Outlook, Apple Mail or a phone app will connect.
- Use IMAP if you read mail on more than one device; POP downloads mail to one device only.
Official page: Xfinity (Comcast) email settings
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Common Xfinity (Comcast) email problems
My old POP setup stopped working
Port 110 no longer works. Change incoming to pop3.comcast.net, port 995, SSL on, or switch to IMAP: imap.comcast.net, port 993, SSL on.
I can't send email from Outlook or my phone
Use smtp.comcast.net, port 587 with TLS (or port 465 with SSL), and turn on authentication. Port 25 does not work.
My apps stopped connecting after I had to reset my password
Type the new password into every app. If it still fails, remove the account from the app, add it again, and check that third-party access is still on.
My old comcast.net address is being closed
Sign in at least once every 24 months. If you are leaving Xfinity, you keep the address only if you signed in to the website within 90 days before disconnecting.
Problems that look the same on every provider
Can't sign in, or the password stopped working
- Sign in on the provider's own webmail page first. If that works, the problem is your mail app, not the account.
- If webmail rejects the password, use the provider's "Forgot password" page. Never use a reset link from an email you did not ask for.
- Many providers now need a separate app password (or their own sign-in screen) for Outlook, Apple Mail and phone apps. Your normal password will not work there.
Not receiving emails
- Check Spam, Junk and any filters or "blocked senders" in webmail.
- Check whether the mailbox is full; most providers stop accepting mail at the storage limit.
- If your app shows nothing new but webmail does, remove and re-add the account in the app using IMAP.
Can't send, or emails are stuck in the Outbox
- Check the outgoing (SMTP) server, port and security on this page against your app; old guides often list ports that no longer work.
- Turn on "My outgoing server requires authentication" and use the same username and password as incoming.
- Large attachments are a common cause. Remove the attachment and try again.
Contacts are getting spam from my address
- Change the password from webmail, then sign out of all other sessions if the provider offers it.
- Check forwarding rules, filters and the reply-to address in settings; attackers often add a hidden forward.
- Turn on two-step verification, and update the password anywhere else you used the same one.
Setting it up on a new phone or computer
- Use IMAP rather than POP so mail stays in sync across your phone, computer and webmail.
- Enter your full email address as the username unless the provider says otherwise.
- If the app offers the provider by name (Yahoo, Google, Outlook), choose that instead of "Other".
Sources: Xfinity: use email programs with Xfinity Email (server settings) · Xfinity: email activity policy. Providers change settings from time to time; their own page is the final word.
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