Using Postfix, if I have the following sasl_passwd file, everything works. sasl_passwd [smtp.gmail.com] user:secret [smtp.comcast.net] user:secret [smtp.suscom.net] user:secret However, when I attempt to use Postfix's sender_dependent_relay_maps feature with a custom sasl_passwd file, an error occurs. This is the modified sasl_passwd file: sasl_passwd user1@xxxxxxxxx user1@xxxxxxxxx:secret user2@xxxxxxxxx user2@xxxxxxxxx:secret user3@xxxxxxxxxxx user3:secret user4@xxxxxxxxxxxxx user4@xxxxxxxxxxxxx:secret Using this configuration produces this error message in the mail log: Sep 23 08:30:03 scorpio clamsmtpd: 100A66: accepted connection from: 127.0.0.1 Sep 23 08:30:03 scorpio postfix/smtpd[37138]: connect from localhost[127.0.0.1] Sep 23 08:30:03 scorpio postfix/smtp[37137]: warning: SASL authentication failure: No worthy mechs found Sep 23 08:30:04 scorpio postfix/smtp[37137]: 359C8BD7A: to=<beerstud@xxxxxxxxxxx>, relay=127.0.0.1[127.0.0.1]:10025, delay=0.84, delays=0.31/0.21/0.31/0, dsn=4. 7.0, status=deferred (SASL authentication failed; cannot authenticate to server 127.0.0.1[127.0.0.1]: no mechanism available) Sep 23 08:30:04 scorpio postfix/smtpd[37138]: disconnect from localhost[127.0.0. 1] I am not sure exactly where the problem is. Worse, I do not understand why it works in one configuration but not the other. -- Gerard 73% of Americans say that immigration is a serious problem. The other 27% said, 'No habla ingles.'