Hi again MailerForum, just had some success with mailing only yahoo for a short time. And I'm very happy with the help some of you provided. But again I have few problem and after some trying and searches being unsuccessful I'm posting here another question. I am getting a lot of TS03 from yahoo from some ip I have, my spam rate is very low for the moment on those ips: like 0.03% rate (I think this is low) For unknown reason yahoo start to give me those infamous TS03. First I tried to bounce the queue immediately once receiving this error. Then I use backoff config into pmta. but error persist even after stop mailing from those ips for about 2 days. Is my ips are dead for yahoo or I'll be able to send mail again ? Thanks a lot in advance for your help.