I've got a weird issue on one of my postfix installations that I can't explain.
My postfix setup uses MySQL as an authentication backend, and the accounts are managed via Postfixadmin. All of our webservers use phpmailer to send out registration notices to users who register on our site. Now, there are plenty of other accounts on this mail server. Once in a while what happens, and ONLY with this one mail account which is used to send out registration emails, is that for no apparent reason SASL Authentication will stop working, but ONLY for that one account. All other accounts are happy to go about their business. It's really weird. I have no idea how to reproduce it, or what is causing it. Needless to say, it is very annoying since we only notice it a day or two later, when we see a lot of "user waiting for email registration" messages in the admin section of our website. Restarting postfix, saslauthd and authdaemon seems to get it working again, at least for a while. This has me totally baffeled. I've turned on detailed debug logging in postfix for just our webservers, so it might be a while before this hits me again. But how weird. So far the only message in the Logs that appears whenever this happens is: warning: www1.domain.com[xx.xxx.xxx]: SASL LOGIN authentication failed: authentication failure It's the same message for all our webservers which act as clients to this postfix server. What I don't understand is, how can authentication suddenly stop working for only this account, while all the other ones still keep working and authenticating? Like I've said, I've enabled debug logging for specific hosts. But that might take a while to produce some insightful results. In the meantime, does anyone have the faintest idea what might be causing a problem here?
