Why are you using Port 25? I will post what the link offered.
To prevent spam and to ensure the security of our network and customers, Comcast no longer supports the use of port 25 for sending email.
IMAP Email Configuration Settings
To configure an email client to use Comcast email (@comcast.net), the following settings should be used for sending and receiving email:
- Incoming Mail Server Name: imap.comcast.net
- Incoming Mail Server Port Number:
- Recommended: 993 with SSL ON
- Only if Needed: 143 with SSL ON
- Outgoing Mail Server Name: smtp.comcast.net
- Outgoing Mail Server Port Number:
- Recommended: 587 (SMTP)
- Only if Needed: 465 (SMTPS)
- SSL Encryption: checked
- Authentication: XFINITY username and password required
Or use POP.
Same outgoing settings, port 587 with SSL checked.
POP Incoming Email Settings
Using POP to retrieve email will cause a less than optimal experience, especially when you use multiple devices to check your email. We strongly recommend IMAP over POP since this will keep your emails in sync across different devices. If you do need to use POP due to any reason, you can use the following connection information:
- Incoming Mail Server Name: mail.comcast.net
- Incoming Mail Server Port Number: 995 (POP3 With SSL)