Wondering if anyone else has had this issue with Yahoo. I have a user who setup his mail to forward to his yahoo account. All of his mail (he changed his forwarding from gmail to yahoo) went to yahoo for about a month.
About a week after the forward was setup, all mail to yahoo is rejected with a 554:Con:b1 error. Now, a year or so later, mail to yahoo is sporadic, sometimes it sends, sometimes I get a 554 for a couple of days and everything clears up for another month or 5. I never seem to get 421 errors, just 521. I remember having horrible problems with Yahoo blacklisting any server at the drop of a hat about decade ago, but I thought they'd mostly pulled their heads out since then. Anything I can do on my end for the occasional yahoo emails (the user in question switched back to gmail) that will make them happier without too much effort on my part? -- When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is probably wrong.
