Yahoo error smtp; 553 5.7.2 [TSS11]


New Member
So we just recently sent our first campaign with mailwizz! I ran into an issue sending to yahoo and aol accounts (both owned by verizon) and got this error code, which prevented any of emails to go to any accounts with yahoo or aol:

smtp; 553 5.7.2 [TSS11] All messages from xxx will be permanently deferred; Retrying will NOT succeed. See

I have been researching this tirelessly, and found some other platforms that ran into the issue, and they said to keep following the yahoo support links. Generally they are just "good practices" that I appear to be fully in line with. Should I perhaps be sending out emails slower or something to avoid this?

I also contacted to yahoo postmaster support before coming here, they asked for my email headers, then gave me auto replies a few times before closing my ticket without any sort of resolution, unfortunately.

Any advice from anyone dealing with this in the past would be greatly appreciated!
In the past, when i had these issues with yahoo, i was able to get whitelisted by getting in touch with them via their postmaster forms. I think that's the only way, and i think you get this because your IPs are on a network bocked by them, if you for instance will use IPs from US, i don't think you will have this problem.