OT: building new server, need MTA advice

[Peter Nitschke]

>We're in the process of building what will be our new web and mail 
>server. We will be hosting several virtual domains and each will have 
>anywhere from a few to a couple of hundred email users. Obviously we 
>will be running MailScanner and also MailWatch. The box is running 
>CentOS 4.4 (it's like RHEL).
>
>Since we're starting fresh on this box, we're not necessarily married to 
>Sendmail like on our other servers. We could stick with Sendmail, or we 
>could move over to Postfix or Exim (anything else worth considering?). 
>We'd like to be able to add new spam-fighting features as they come out, 
>such as the greet-pause and such. Over the years we've used Sendmail, 
>I've found it a bear to tweak so have done the absolute minimum with it. 
>We're looking for something that is secure, efficient, maintained (which 
>rules out qmail) and easy to administer. Whatever we look at needs to 
>play very nicely with MailScanner or it's not worth considering. 
>Finally, (and I'm not sure it makes a difference to the MTA), we need 
>our users to be able to log in with the "username at domain.tld" format 
>because that's what they use now and I don't want to have to change 
>hundreds of user's email client settings.
>
>Now for the big question: Is there an MTA that should we consider using 
>instead of Sendmail?

I added a couple of lines to sendmail.mc that allowed me to tune it easier,
things that have defaults in sendmail.cf that I wanted to adjust.

Apart from that, after having used sendmail for a few years, I find the
later versions very easy to work with, and use minimal changes from the
default settings.

Peter