Thursday, June 01, 2006

Sendmail SmtpGreetingMessage

Call me old fashioned, but I still use sendmail. Yeah, I know there are lots of more modern and easy to use MTA's out there but I don't have the time to learn them right now. Sometimes best to stick with what you know. Anyhow...

I was wondering how to change the greeting message on an smtp connection and a long search through my O'Reilly sendmail 3rd Edition provided the answer. The following is an mc configuration for versions 8.7 or above:


Where "message" is a string that must at least contain the localhost name. By default message would be:

$j Sendmail $v/$Z; $b
In which results in something like:

220 ESMTP Sendmail 8.13.6/8.13.6; Thu, 1 Jun 2006 23:19:51 +0100


$j = fully qualified hostname
$v = sendmail version
$Z = configuration file version
$b = current date and time

I placed this new definition in my

define(`confSMTP_LOGIN_MSG',`$j MTA ready and waiting ; $b')
Which displays:

220 ESMTP MTA ready and waiting ; Fri, 2 Jun 2006 00:06:08 +0100

Why did I do this? Well it's usually better with sendmail (or indeed any MTA or service) to hide the version from the outside world as this can make it a little harder to exploit.

No comments: