Filtering by SASL auth mechanism

Hi all,

I want dovecot to behave differently depending on what SASL mechanism was used. Most specifically, if EXTERNAL, I want auth_ssl_username_from_cert to be yes, but no otherwise.

There is a filtering mechanism that supports protocol, remote, etc.

https://doc.dovecot.org/configuration_manual/config_file/

Would it make sense to add a SASL mechanism filter like this:

mechanism external { # … }

Regards, Graha —