We are running Postfix and require authentication for the sending of mail through SMTP. The authentication uses Cyrus' saslauthd which does a Kerberos authentication against our Kerberos domain.
Is there a way to tell saslauthd to attempt authentications only to the Kerberos domain MYDOMAIN.ORG and to simply reject any other domains? That is, to not even try to authenticate for other domains?
Or, if saslauthd does not allow that, can Postfix be configured to reject authentication attempts from users with domains other than ours?
We are running all of this on Debian buster (sasl version 2.1.27, postfix 3.4.14).
