SASL LOGIN authentication failed: authentication failure

I've followed the following tutorial:
http://www.howtoforge.com/virtual-users-domains-postfix-courier-mysql-squirrelmail-centos-5.3-x86_64

Everything is working fine except smtp authentication. When I try to send mail I get the following in maillog

Code:

Sep  2 10:21:40 domain postfix/smtpd[21857]: connect from nat-...
Sep  2 10:21:40 domain postfix/smtpd[21857]: warning: nat-...: SASL LOGIN authentication failed: authentication failure
Sep  2 10:21:40 domain postfix/smtpd[21857]: disconnect from nat-...

Any help with this error would be greatly appreciated. Just let me know what files you would like me to post that would help in debugging this issue.

Thanks for your time.

 

Did you disable SELinux?

 

Thanks for your reply Falko.

I was actually updating the wrong smtpd.conf file and as soon as I updated the correct one everything started working fine.

This thread can be closed, thanks.