Ok, I consider myself a "newbie" when it comes to MTAs.
I currently run sendmail, but I've done as little as possible to get it working. I have no spam filtering at SMTP, no auto-sorting of messages into folders, basically nothing more than "get the mail to the spool".
Why? Because sendmail frightens me, I'm lazy, and what I have now basically "works" and I don't want to break anything.
I've run sendmail, qmail and postfix.
I had a love affair with qmail -- I used to love how it would push the load average on my little cobalt qube (16 M of RAM) to 20 while sending more than 1000 messages per minute.
In bigger installations I had all sorts of trouble, but the killer is that Dan Bernstein doesn't want to maintain qmail and his license doesn't let anybody fork it. You ~can~ put together a system that can do spam filtering, sender authentication, you name it, but you're going to put in a ~lot~ of patches and have a frankensystem that's different from anybody elses frankensystem.
I've run a postfix installation, and I've been pretty happy with it. It's pretty easy to set up virus and spam filtering with postfix, and cyrus is a great back end, although there's more system integration involved than average newbie would want. I had trouble during the virus crises last year, and had to abandon an old email address that would get 50,000+ viruses a day. (/var fills up with log entries from the virus checker, etc.) Since then the system will go for months without intervention.
I've had a job where we use sendmail, and have even had to deal with RHEL 3 kernel bugs that caused sendmail to fail. (Upgrade to 2.6 solved this)
Sendmail isn't so bad, but the trouble is that the online documentation is useless; if you can get the big O'Reilly book on it, Sendmail isn't hard to configure at all.
I think Alan's wrong to suggest that there's no middle ground between caring about how easy stuff is to configure, and needing a complete point-and-drool configuration GUI for it. We don't _have_ a GUI configuration tool for any MTA, but we do have a web browser and the excellent and fully indexed Exim documentation, and a bunch of useful default features commented out but ready to use in the default config file.
I really like the way configuration files work in Red Hat and Fedora. I love /etc/sysconfig.
I hate the graphical configuration tools. It's not that I hate the idea of them; the user interfaces for most of them are sound. (They ought to be since they rip off Windows)
The trouble is that the authors seemed to quit working on them at the time they reached the 80% working level. A graphical configuration tool that screws up occasionally and needs workarounds is a big waste of time -- particularly when I know my way around /etc/sysconfig and can make any changes I want in thirty seconds with "sudo emacs."
I'm all for graphical configuration tools, but configuration tools that work 80% are worse than graphical configuration tools that don't work at all.
