A few weeks ago we told you about AOL’s migration of their MX servers to Yahoo’s infrastructure as part of the merger of the two entities under Verizon’s new Oath brand. Since that change in early February, mail to AOL recipients has been handled by Yahoo’s servers. No specifics have been released on how the combined mail system will handle filtering, but observations of recent bounces may shed some light on that.
Over the past 2-3 weeks a number of senders have been seeing the dreaded “Yahoo deferrals” from recipients with AOL email addresses. These deferrals – temporary bounces usually caused by a high complaint rate – occur frequently for many high-volume senders mailing Yahoo recipients. These bounces are typically returned in a format similar to the following:
421 4.7.0 [XXXX] Messages from XX.XX.XX.XX temporarily deferred due to user complaints – X.X.X.X; see https://help.yahoo.com/kb/postmaster/SLN3434.html
The appearance of these types of bounces when sending to AOL recipients means you now have to contend not only with AOL’s spam filtering but with that of Yahoo. While AOL is known for its useful resources and responsive Postmaster team, the Yahoo Mail team can be more difficult to reach when issues arise. If you do run into any of these bounces, it’s probably a good idea to reach out to Yahoo via their Support form since the filtering is occurring on their mail servers.