On 19/11/2020 12:55 sebastiano degan sebastiano.degan@frigoveneta.it wrote:

On a Debian10 I've installed postfix 3.4.14 and dovecot 2.3.4.1. I've configured multiple passdb sources and I expect that if one fails the other ones are tested. This is usually the case, except when the failure is due to an invalid certificate from the ldap server. In that case all authentication attempts from that moment on will fail.

Hi!

Can you try with latest CE release from https://repo.dovecot.org/

Regards, Aki