[...]
Is it possible to change banner without having to re-compile the Sendmail sources??? I've had a look to /etc/sendmail.cf. There is an entry which contains "DZ8.9.3/SuSE Linux 8.9.3-0.1". So I suppose there will be no problems if I change it to any string I want. But... could I remove the "Sendmail" string or simply remove the banner completely and change to "220 machine_name.domain Microsoft Mail Server"??? I think I'd have to recompile Sendmail... (not the db's, I'm referrering to the sendmail source code)-
I think you'll have to recompile sendmail to do this. However, I recommend using Postfix as SMTP daemon - it is belived to be more secure than sendmail. Postfix (main.cf): smtpd_banner = $myhostname ESMTP Server ready
The question extends to any other daemons like Proftpd, Qpopper,
Proftpd (proftpd.conf): ServerIdent on "FTP Server ready" DeferWelcome on QPopper: Recompile with ./configure --enable-shy
PS: Banners are very important to hackers (or at least script-kiddies) wanting to penetrate your machine.
I totally agree... -- Ørnulf Nielsen Linux Communications AS