Every desktop distro I've installed has had either sendmail or postfix as part of it's base install.

But sendmail, in particular, is a pain. It always delays startup while it protests that I don't have a domain. I don't want a domain! I don't need a domain. When I send email, Thunderbird or mutt or mailx sends it to my ISP. My ISP has a domain. The PCs on my house network don't have any domain.

I've often thought I could just remove it. So when I recently installed CentOS (in a virtual machine), I immediately tried to remove postfix. But yum said it was going to remove cronie too. (Cronie is the version of cron that the the RedHat world uses.) But I need cron.

Why can't I remove postfix without removing cron?

you can! they just don't want you to b/c cron tries to send emails, i think.

anyway, to force the removal:

I assume the dependency is there as cron might send an email too. It can only contact a local service and postfix will forward the mail (it’s like sending an email from the command line).