a probable solution for you
I've seen this with a number of people, beginning last week with the "new aol". Now, without letting anyone in on the secret, at the drop of a pin you can be labeled as sending spam. This amounts to a block on your sending mail. To undo it you must go to: challenge.aol.com/spam/html
There you put in your email address, password and it will unlock your sending mail.
Yes, aol does it again.