Outgoing emails cannot be sent

user_65eihj Thank you for reaching out! Since the Xfinity webmail site sends emails successfully and the iPhone can receive mail, you would want to focus specifically on the outgoing SMTP configuration/authentication in Apple Mail.

 

Go to Settings, Apps, Mail, Mail Accounts, Comcast account, Account, SMTP, Primary Server and verify:

 

Host Name: smtp.comcast.net
Username: the full Comcast.net email address, including @comcast.net
Password: Re-enter the current Xfinity password manually. If you copy and paste, ensure there is no extra space at the end. 
Use SSL: On
Authentication: Password
Server Port: 587
If 587 does not work, try 465 with SSL/TLS.