Outgoing emails shunted to Outbox

Continuing problem with outgoing emails being shunted to Outbox and killed, regardless of their size or whether or not they have attachments.

This was a noted problem for many in 2018.  Supposedly, a new server needed fixing.  It has reappeared again .  Makes me want to dump Comcast email forever, although I've had the same account since Comcast began.

Wassup???