postfix and smpt

Hi,

I've followed the excellent 'Email with Postfix, Dovecot, and MySQL' guide.

I can connect using pop but when I try SMTP the mail log says:

Dec 16 20:24:02 www postfix/smtpd[30644]: lost connection after EHLO from unknown[37.152.252.222]

Dec 16 20:24:02 www postfix/smtpd[30644]: disconnect from unknown[37.152.252.222]

Dec 16 20:24:02 www postfix/smtpd[30644]: connect from unknown[37.152.252.222]

Dec 16 20:25:37 www postfix/smtpd[30644]: lost connection after EHLO from unknown[37.152.252.222]

Dec 16 20:25:37 www postfix/smtpd[30644]: disconnect from unknown[37.152.252.222]

Dec 16 20:25:37 www postfix/smtpd[30644]: connect from unknown[37.152.252.222]

The client says ' cannot safely connect to server'.

Any thoughts would be welcome.