I use freebsd 7.3

I installed iredmail0.6rc on it. all services has started.
pop3 and imap services works

But I can't send a mail using smtp service
When I try to send an email, I get an error;

ay 30 23:35:33 postfix postfix/master[18543]: warning: process /usr/local/libexec/postfix/smtpd pid 18548 exit status 1
May 30 23:35:33 postfix postfix/master[18543]: warning: /usr/local/libexec/postfix/smtpd: bad command startup -- throttling
May 30 23:36:33 postfix postfix/smtpd[18556]: warning: SASL: Connect to smtpd failed: No such file or directory
May 30 23:36:33 postfix postfix/smtpd[18556]: fatal: no SASL authentication mechanisms
May 30 23:36:34 postfix postfix/master[18543]: warning: process /usr/local/libexec/postfix/smtpd pid 18556 exit status 1
May 30 23:36:34 postfix postfix/master[18543]: warning: /usr/local/libexec/postfix/smtpd: bad command startup -- throttling

How can I correct that?