With the upgrade of the mailing list software, this policy is no longer in effect.
Due to email policies from various email providers (AOL & Yahoo, specifically), we are unable to allow posts from the aol.com & yahoo.com email addresses (among others).
aol.comaim.comcs.comAll yahoo domains
The gist of the issue is that the email providers have implemented a DMARC policy that prohibits any server, other than ones they control, from sending a message using their domain’s from address.
Other mail servers will see this policy and automatically reject any mail that has that specific domain but doesn’t come from an approved list of mail servers.
This results in mail bouncing with a fatal error (5xx return code), which our mailing list software will interpret as a fatal bounce. Subscribers with too many fatal bounces will be unsubscribed from the lists.
We are working on a solution but, until it is implemented, we cannot allow posts from those domains.
For details on the cause, see this page.