On Mon, Apr 19, 2010 at 11:37 AM, Wietse Venema <wie...@porcupine.org>wrote:
> Gaby L: > > Hi > > I scan with my postfix server with NMap from other location. > > The NMAP creats report smtp port open (It is OK) but apear Postfix smtpd > and other information about MTA program. > > I dont want to apear any information about my MTA server. > > To disclose no information, close the SMTP port. > > Seriously. > > Even when you change the smtpd_banner value to say "$myhostname > ESMTP Sendmail" (this text MUST start with the hostname), the > server's replies (especially error messages) still reveal that it's > really Postfix. > > Wietse > Disclaimer :- It may violate some RFCs and possibly break the smtp system itself. [r...@stick ~]# grep ^smtpd_banner /etc/postfix/main.cf smtpd_banner = "unknown" [r...@stick ~]# telnet 0 25 Trying 0.0.0.0... Connected to 0. Escape character is '^]'. 220 "unknown"
