I am running Debian 8 with Virtualmin, and at some point about a month ago something changed (no doubt by me, but I no longer know what it might have been...) and I did not catch it until now. At this point, I am getting errors like the following in mail.err, and I have a bunch of messages in the queue that have been there starting June 25..
Jul 18 14:31:32 olympus postfix/qmgr[14624]: fatal: timeout connecting to transport: smtp Jul 18 14:31:41 olympus postfix/smtp[31960]: fatal: specify a password table via the `smtp_sasl_password_maps' configuration parameter
Any ideas?
I 'fixed' the issue by renaming smtp_sasl_auth_enable to smtpd_sasl_auth_enable in main.cf. Apparently this disables sasl_auth, so I will have to fix that, but at least I can send mail again for the time being.