Postfix - Can't Send Email To Yahoo Only


Our server can not send email to yahoo since first virtualmin install, dkim, spf working fine also ip clean from any blacklist. Another yahoo email are work best.

Postfix mail queue:

host[] said: 421 4.7.0 [TSS09] All messages from temporarily deferred due to user complaints -; see (in reply to MAIL FROM command)

 delivery temporarily suspended: lost connection with[] while sending RCPT TO

I tried a variety of postfix tutorials on google and see the problems here but to no avail.

Since I have saved a lot of emails, does anyone have a complete tutorial how to move to the exim mail server without interrupting existing email?

Please share any idea mate

  1. Do you have properly set rDNS, SPF and DKIM?
  2. Did you sent intentionally or not unsolicited emails?
  3. Did you fill up the Yahoo form for mass mailing (in case you are doing it)?
  4. Bonus: Did you set DMARC?

If after all this you still have problems then only option left is to contact Yahoo and work with them as no one here can help you with your problem.

Tanks sir diablo,

All your mentioned has been checked.

Before migrating to virtualmin, i’am use cpanel, all mail work fine, since migrating our mail to yahoo not working, i assume maybe postfix configuration not good for yahoo servers :slight_smile:

How to switch mailserver to exim?