I can no longer send emails from Apple Mail on El Capitan.
Every time I try to send an email, from my comcast.net account, a window appears asking for my password. I type it in and it says that it is "unable to verify the username or password".
BUT, it does receive all my incoming emails from the same account. So clearly the password is correct.
So I decided to change the password via Xfinity website, then updated it on my iMac. Still has the same problem.
When I launch my computer in Safemode, still has the same problem.
Notably, I can use this email account without any problem on my iPhone and my iPad, and my MacBook Pro. It is only a problem on the iMac OS 10.11.6.
Also notably, I have two other email accounts set up in Apple Mail -- iCloud and Gmail. Both are able to send and receive emails no problem.
I made sure to do a System Update that was available.
So I decided to just delete the comcast account from my Internet accounts, and then recreate it. Well now I can NOT add it as a new account anymore. When I try to add it, I get the same message. "Unable to verify account name or password" see screen shots attached.
Additionally I spent over 2 hours via chat and phone with Xfinity support. Basically they just had me try everything I had already tried myself. Then said they were going to write a trouble ticket and then get back to me within 40 minutes, which they did not.
iMac, OS X 10.11
