Debian - Postfix - Unable to send e-mail @yahoo

Posted September 23, 2014 8.9k views

Hi, I’m French, so first excuse me for my english.

My problem is that I can not send an e-mail to

Here is the message in log (mail.log) :

Sep 23 10:10:31 jeremydevos postfix/smtp[21221]: 93487411BA: to=<>,[]:25, delay=0.4, delays=0.01/0.04/0.13/0.22, dsn=4.7.1, status=deferred (host[] said: 421 4.7.1 [TS03] All messages from will be permanently deferred; Retrying will NOT succeed. See (in reply to MAIL FROM command)).

With MXTOOLBOX everything is OK :

SMTP Banner Check   OK - resolves to
    SMTP Reverse DNS Mismatch   OK - Reverse DNS matches SMTP Banner
    SMTP TLS    OK - Supports TLS.
    SMTP Connection Time    0.905 seconds - Good on Connection time
    SMTP Open Relay     OK - Not an open relay.
    SMTP Transaction Time   3.245 seconds - Good on Transaction Time

Thank you for your help

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1 answer

That looks like yahoo has permanently blacklisted your ip. At some point in time a spam server was most likely using that ip.

About the only thing you can really do is get new ip. Unless someone has an easier method the only way I can think of doing this is by:

  1. Snapshot the server.
  2. Recreate server from snapshot.
  3. Update all the DNS entries A recrods MX, etc records and such point to new ip.
  4. Destroy original server

Good luck.