# tail /var/log/mail.log
Aug 28 17:16:35 t300 postfix/smtpd[3526]: connect from adm.xxx.com.br[189.xxx.xxx.5]
Aug 28 17:16:35 t300 postfix/smtpd[3526]: warning: SASL authentication failure: cannot connect to saslauthd server: No such file or directory
Aug 28 17:16:35 t300 postfix/smtpd[3526]: warning: adm.xxx.com.br[189.xxx.xxx.5]: SASL LOGIN authentication failed: generic failure
Aug 28 17:16:35 t300 postfix/smtpd[3526]: lost connection after AUTH from adm.xxx.com.br[189.xxx.xxx.5]
Aug 28 17:16:35 t300 postfix/smtpd[3526]: disconnect from adm.xxx.com.br[189.xxx.xxx.5]
Edit file: /etc/postfix/sasl/smtpd.conf
Insert line: saslauthd_path: /var/spool/postfix/var/run/saslauthd/mux
/etc/init.d/postfix restart
/etc/init.d/saslauthd restart
resolved problem!!
Thanks very much to this
http://www.howtoforge.com/comment/reply/4564/18062