Short tip: postfix - SASL authentication failure: No worthy mechs found

If you install and configure a Postfix mail server for relaying mails using an external smarthost you might be puzzled about the following error message:

1Mar 19 17:00:22 hostname01 postfix/smtp[2003]: warning: SASL authentication failure: No worthy mechs found

The reason for this issue can be really trivial - in my case I did a minimal installation of RHEL which came without SASL and the appropriate plain module.

Installing the needed libraries fixed the problem for me:

1# yum install cyrus-sasl{,-plain} libsasl2-modules

If appropriate SASL modules are present you might have a deeper look at the Postfix main configuration file /etc/postfix/main.cf:

  • typing errors?
  • SASL SMTP password map missing or erroneous? (postmap?)
  • SASL SMTP  security options missing or erroneous?
  • sender_canonical missing?

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