Thanks for the quick reply Jeroen, But it looks reject_non_fqdn_sender doesn't help:
[r...@rhel5 postfix]# grep fqdn main.cf smtpd_sender_restrictions = reject_non_fqdn_sender non_fqdn_reject_code = 501 [r...@rhel5 postfix]# postfix reload postfix/postfix-script: refreshing the Postfix mail system [r...@rhel5 postfix]# /etc/init.d/postfix restart Shutting down postfix: [ OK ] Starting postfix: [ OK ] [r...@rhel5 postfix]# !telnet telnet localhost smtp Trying 127.0.0.1... Connected to localhost.localdomain (127.0.0.1). Escape character is '^]'. 220 formail.localdomain ESMTP Postfix HELO ME 250 formail.localdomain MAIL FROM:<XYZ> 250 2.1.0 Ok <========== Still Ok As to the return code, either is OK. I just want to inform the user his MAIL FROM syntax is wrong. Any ideas? Thanks, Mingliang
