Hey guys! Not sure where to put this question but here we go... I am currently having alot of trouble with Yahoo/AOL delivery after their migration into Oath. After several days of testing and twisting my PMTA Config I'll try to reach out here instead. I keep receiving: "421 4.7.0 [TSS04] Messages from XX.XX.XX.XX temporarily deferred due to user complaints - 126.96.36.199; see https://help.yahoo.com/kb/postmaster/SLN3434.html" received from mta5.am0.yahoodns.net (188.8.131.52) while connected from Mydomain.com (XX.XX.XX.XX) to mta5.am0.yahoodns.net (184.108.40.206)" I've been at the provided link from Yahoo, but not much useful there and I am pretty sure it has nothing to do with user complaints. Since this happens after the first 3-5 Emails on all my servers. So that means some kind of unusual activity from my mail server. I've split up the different Yahoo MX's. Since they got 3 different "entry points" and cant delivery a aol.com mail by using Yahoo.com MX fx. So: - AOL MX - mx-aol.mail.gm0.yahoodns.net - Yahoo.com MX mta5/6/7.am0.yahoodns.net - Yahoo EU MX - mx-eu.mail.am0.yahoodns.net I've tried with queues, mx-rollup and grouping all together. Still receiving this on all servers. I got these settings for each queue/mx. Since I am warming up the IP's. max-smtp-out 1 max-msg-rate 60/h max-msg-per-connection 5 It let's me delivery 3-5 Emails before giving me the Error message. Retry after 1 hour, 3-5 Emails... And repeat. So my question is if anyone have experienced the same and found somekind of solution? People in here is often good at being helpful so hoping someone can help me a bit or able to give any advise regarding this? I can be reached in this thread of by PM.