After upgrading Debian on a ISPConfig server, I get postfix SASL errors when sending mail: postfix/smtps/smtpd[14115]: warning: unknown[x.x.x.x]: SASL LOGIN authentication failed: (reason unavailable), [email protected] Any hints about why this is happening and how to debug it? I think postfix uses dovecot for SASL authentication, but I don't get any debug messages, even with auth_verbose = yes in 10-logging.conf I also got Dovecot errors: Invalid password in passdb: Weak password scheme 'MD5-CRYPT' used and refused, but I could solve those by updating the mail password.
Have you run an ISPConfig update with 'reconfigure services' set to 'yes' after upgrading Debian? And do you use any custom configurations for Postfix and Dovecot?
I reconfigured services. I have one custom configuration for rspamd, but that doesn't seem to be the problem. Because it's a server that has been upgraded from something like Debian 7 to 13, I've also tried removing postfix and dovecot completly and starting with a clean configuration (only copying my SSL certs back). And running ispconfig_update --force again. But no luck yet... Where should I look for clues? The logfiles don't seem to contain much right now.
Incoming mail is delivered, so that part of postfix works. Also imap and pop work and sending mail via webmail works (since it doesn't need SASL auth)
Do logins with Dovecot work using the same username and password? And as you said, Postfix uses Dovecot as an authentication provider.
My postfix config file is a historic mess... there must be something evil in it, because it does work with a clean /etc/postfix directory (remove all files and reinstall postfix). After that, I did the standard changes to the new postfix configuration and ran ispconfig_update --force again. I think some of the configuration in the old config file was there for a reason but there is probably also something in there that breaks things. I will go through it line by line.
Sorry for the confusion, at least it is clear the problem is not in ispconfig or standard postfix config!
