Here’s an interesting situation with a host I use. AOL is getting confused as to the actual source of email marked as spam, and mail forwarding servers are getting dinged as a result.
[…] some customers have content filter rules to send all mail for their domain or for their mailbox to @aol.com addresses. These customers then go into their @aol.com accounts and read their mail and mark messages as spam. When these customers mark messages as spam, AOL now has counters in place that record the mail server it came from.
Therefore, in order to meet the guidelines and thresholds imposed by AOL, we will soon be shutting off the ability to forward emails to @aol.com addresses.
Crappy situation, but I can see why they have no choice but to shut off forwarding.