I added the debug command you requested so you can see the whole error. I don't seem to have dns issues so i haven't felt the need for the brackets. I do seem to have the NTLM module
I am aware of base64, so my tests with telnet i did use base64 to enter the username but as soon as i pressed enter i got the errors i posted. I wanted to find out the proper username syntax so i could edit the sasl password file properly. My tests are being done with the sendmail command. I don't know how to configure the linux box properly, so users by default try to use the sendmail command as "u...@mydomain.com" instead of "u...@helpdesk.mydomain.com". This box is being configured as a helpdesk therefore it has a "helpdesk" hostname. syslog.txt <http://postfix.1071664.n5.nabble.com/file/n65074/syslog.txt> -- View this message in context: http://postfix.1071664.n5.nabble.com/Exchange-2007-gives-535-5-7-3-Authentication-unsuccessful-tp65072p65074.html Sent from the Postfix Users mailing list archive at Nabble.com.