Email server settings
Comcast IMAP settings and Xfinity SMTP server
The Comcast IMAP settings are imap.comcast.net, port 993, SSL on, with your full comcast.net address as the user name. Outgoing mail goes through smtp.comcast.net on port 587 (or 465). Before any mail app can connect, turn on third-party access in Xfinity Email.
Last checked October 9, 2026, against Xfinity’s own documentation.
Comcast (Xfinity) email servers
| Server, port and securityServer | Port and security |
|---|---|
| IMAP · incomingimap | 993SSL/TLS |
| IMAP · incomingimap | 143STARTTLS |
| POP3 · incomingpop3 | 995SSL/TLS |
| SMTP · outgoingsmtp | 587STARTTLS |
| SMTP · outgoingsmtp | 465SSL/TLS |
Sign-in: Full address + Xfinity password
User name: your full Comcast address, for example jane.doe@comcast.net; the password is your Xfinity password.
Xfinity IMAP and SMTP settings in detail
Xfinity’s article on email client settings is the source. Comcast email and Xfinity email are the same service: the addresses end in @comcast.net, and the servers are the same whether your app says Comcast or Xfinity.
- Use IMAP. Mail and folders stay on the server, so every device sees the same inbox. POP3 downloads messages and removes them from the server, which causes trouble as soon as you read mail on a second device.
- Comcast SMTP settings:
smtp.comcast.neton port 587 with TLS, or port 465 (SMTPS) if needed. Port 25 is not supported, for security and anti-spam reasons; Xfinity notes that older programs such as Outlook Express, Outlook or Mac Mail may have trouble sending because of it. - POP3 port 110 is gone. If you still use POP, it’s
pop3.comcast.neton 995 with SSL. (Autoconfiguration data in some mail apps still listsmail.comcast.netand port 110.) - Log in for sending too. Turn on authentication for the outgoing server with the same address and Xfinity password; Xfinity says sending requires your Xfinity ID and password.
Turn on third-party access first
Xfinity blocks mail apps until you allow them (Xfinity: third-party email access):
- Sign in to the Xfinity Email website with your Xfinity ID and password.
- Select the gear icon in the top-right corner, then Settings.
- Select Security.
- Under Third Party Access Security, check the box that allows third-party programs.
The box is already checked if you have used a mail app with the account before, and unchecked if you haven’t. While it’s unchecked, adding the account to a mail app ends with an error message. Xfinity warns that third-party programs can expose your Xfinity ID and password to fraud and can read, download or delete your email, so only allow apps you trust.
Xfinity’s help pages don’t describe app passwords for email: mail apps log in with your full comcast.net address and your Xfinity password.
Comcast IMAP settings for iPhone, Outlook and Thunderbird
iPhone and iPad (Xfinity links to Apple’s instructions; the values are Xfinity’s):
- Turn on third-party access (above).
- Open Settings → Apps → Mail → Mail Accounts → Add Account, enter your address and tap Next.
- Tap Add Other Account → Mail Account, enter your name, address, Xfinity password and a description, and tap Next.
- If Mail doesn’t find the settings itself, choose IMAP. Incoming Mail Server: host
imap.comcast.net, your full address as user name. Outgoing Mail Server: hostsmtp.comcast.net, same user name and password. - Tap Save. If sending fails, check the outgoing server under the account’s advanced settings: SSL on, port 587 (or 465).
- Outlook: add the account, choose IMAP in the advanced or manual setup, and enter
imap.comcast.net(993, SSL/TLS) andsmtp.comcast.net(587, STARTTLS). Check that the outgoing server requires authentication with the same login. If an old profile still uses port 25 or POP on 110, edit it. - Thunderbird: Thunderbird usually configures Comcast on its own. Compare the result with the table: IMAP 993 SSL/TLS, SMTP 587 STARTTLS, with your full address as user name.
- Android: in Gmail or your phone’s mail app, add an Other or IMAP account with the same values.
Common Comcast email errors
| Error or symptom | Fix |
|---|---|
| Error message when you add the account in a mail app | Third-party access is off. Turn it on under Settings → Security → Third Party Access Security in Xfinity Email, then try again. |
| Sending fails or times out, receiving works | The app uses port 25 or no authentication. Set smtp.comcast.net to port 587 with TLS (or 465 with SSL) and log in with the full address and Xfinity password. |
| POP stopped working on port 110 | Port 110 is no longer supported. Use pop3.comcast.net on 995 with SSL, or switch to IMAP. |
| Messages missing on your phone or second computer | One device uses POP and removes mail from the server. Switch all devices to IMAP. |
| Password rejected after you changed your Xfinity password | Update the password in the mail app for both the incoming and the outgoing server. |
If a message to someone else bounces, the reply code tells you why: see the SMTP error codes and the difference between a hard vs. soft bounce.
Is @comcast.net a valid email domain?
Yes. comcast.net is the email domain of Comcast’s Xfinity customers; Xfinity’s own help calls them “Comcast.net” addresses. A comcast.net address is still no proof that the mailbox is in use: an address that worked years ago may have been closed since, and mail to it then bounces as a hard bounce.
Before you mail an old list with many comcast.net contacts, run it through a bulk email verifier, or check a single contact with our free check Is this a real email address?.
About the address domain: Is @comcast.net a valid email domain?
Sources
Checked on October 9, 2026. Server names, ports and sign-in rules come from these official pages:
Other internet providers
Comcast email settings: FAQ
What are the Comcast IMAP settings?
imap.comcast.net, port 993, SSL on; if that fails, port 143 with STARTTLS. User name: your full comcast.net address, password: your Xfinity password. Turn on third-party access in Xfinity Email first.What is the Comcast SMTP server?
smtp.comcast.net on port 587 with TLS, or port 465 with SSL. Port 25 isn’t supported. Log in with your full address and Xfinity password.What are the Comcast IMAP settings for iPhone?
imap.comcast.net as the incoming and smtp.comcast.net as the outgoing server, both with your full address and Xfinity password.Why can’t my mail app connect to Xfinity email?
Does Comcast still support POP3?
pop3.comcast.net port 995 with SSL, but Xfinity doesn’t recommend it, and port 110 is no longer supported. IMAP keeps mail in sync across devices.Email validation API
Validate comcast.net addresses before you send
emailvalidation.io checks syntax, MX records and the mailbox over SMTP, flags disposable, role and free addresses and returns a quality score, in one request.
/v1/info Email validation API Read the documentation
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GET https://api.emailvalidation.io/v1/info?
{
"email": "support@emailvalidation.io",
"user": "support",
"tag": "",
"domain": "emailvalidation.io",
"format_valid": true,
"mx_found": true,
"smtp_check": true,
"catch_all": null,
"role": true,
"disposable": false,
"free": false,
"score": 0.64,
"state": "deliverable",
"reason": "low_quality",
"did_you_mean": "",
"catch_all_resolution": null,
"bounce_probability": null,
"status": "valid",
"sub_status": "role_based",
"explanation": "The mailbox exists, but it is a role address (such as info@ or support@), usually read by a team rather than one person.",
"recommended_action": "send_with_caution"
}