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.
AOL posted on their blog today about changes to DMARC reporting and FBL messages as they continue to transition domains to the OATH infrastructure. As AOL domains go to the new infrastructure, DMARC reports for those domains will be included in the existing Yahoo DMARC reports.
After the MX migration is done, they’ll start migrating the actual user mailboxes. Right now, FBL messages for AOL properties are coming from AOL and will continue to do so until the actual mailbox is transitioned to the new infrastructure. Once the mailbox is transitioned, then any FBL emails from that address will come from the Yahoo infrastructure. The blog post at AOL suggests signing up for both AOL and Yahoo FBLs during this transition phase.
It does bring up an interesting question as to whether or not the combined FBL is going to be IP based, DKIM based or a mix of both. It sounds like at least during some part of the consolidation there will be a DKIM only FBL. It could be that there will be some expansion to an IP system in the future. Or, it could be that all FBLs from AOL addresses will be based on DKIM domain.
A number of people have mentioned over the last couple weeks that they’re seeing a spike in Yahoo rejecting mail with
554 delivery error: dd Requested mail action aborted
Discussions on various mailing lists indicate these messages are related to inactive accounts. Addresses that bounce at Yahoo with these codes should be handled as inactive addresses and removed from future mailings.
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.