telnet localhost 25でConnection closed by foreign host.

$ telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Connection closed by foreign host.

/var/log/mail を見るとこんな感じのログが

Feb  8 09:43:20 www3075ue postfix/smtpd[12732]: connect from localhost[127.0.0.1]
Feb  8 09:43:20 www3075ue postfix/smtpd[12732]: warning: SASL: Connect to private/auth failed: No such file or directory
Feb  8 09:43:20 www3075ue postfix/smtpd[12732]: fatal: no SASL authentication mechanisms
Feb  8 09:43:21 www3075ue postfix/master[23716]: warning: process /usr/libexec/postfix/smtpd pid 12732 exit status 1
Feb  8 09:43:21 www3075ue postfix/master[23716]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling