Why can't I send mail to AOL Mail users?
If you're repeatedly getting delivery failure errors when sending messages to AOL Mail customers, it is most likely due to spam blocking on AOL's servers. While you may be following at the rules for sending mail, it's likely the address you're sending mail from is hosted on a server our system had identified as "abusive".
To restore your ability to email AOL members, ask the administrator of your email domain to submit a request to the AOL Postmaster support team. The process to review these requests can take anywhere from a few hours to a few weeks to complete.