The Yahoo bounce problem has been resolved. There were erroneous ‘554: this user does not have a yahoo.com account’ between March 14 and March 16. If you attempted to send mail and received this bounce during that time you can reactivate the address in your database. Most ESPs should be able to help you with this.
Moving forward, though, these bounces are valid and addresses should be removed from your list according to standard data hygiene processes.
Multiple folks are mentioning seeing an increase in “user unknown” responses from Yahoo. Some people are discussing this with Yahoo.Right now, best advice is to believe these are accurate user unknowns. UPDATE: There is increasing evidence these are not valid user unknowns. See next post.
I still don’t have any solid information on the cause of the Yahoo bounces. I do know that folks inside Yahoo are looking into the issue.
However, multiple people (including my clients) are reporting that the addresses that are bouncing have very recent click and open activity. Other reports say these addresses deliver on a resend.
It looks like my advice yesterday was incorrect. I’m currently telling clients to continue mailing addresses for the time being.
We’ve known for a while that AOL email infrastructure is going to be merging with Yahoo’s, but apparently it’s happening sooner than anyone expected.
The MXes for aol.com will be migrated to Yahoo infrastructure around February 1st. Reading between the lines I expect that this isn’t a flag day, and much of the rest of the AOL email infrastructure will be in use for a while yet, but primary delivery decisions will be made on Yahoo infrastructure.
The AOL and Yahoo postmaster teams are pretty smart so I assume they’ll have made sure that their reputation data is consistent, and be doing everything else they can do to make the migration as painless as possible. But it’s a major change affecting a lot of email, and I wouldn’t be surprised to see some bumpiness.
If you’ve done anything … unwise … with delivery to AOL addresses, such as hard-wiring MXes for delivery to aol.com, you should probably look at undoing that in the next week or so. I’m guessing the changeover will happen at the DNS level, so if you’ve nailed down delivery IPs for aol.com you might end up trying – and probably failing – to deliver to the old AOL infrastructure.