I have been doing it for years and it is not that big a deal once it is configured.
If you want to get fancy then it can be a problem.
We run courier (I wanted sendmail but lost ) using imap to our local net.
it runs on a local virtual machine and is pretty much maintenance free.
It can not be accessed from outside (the "fancy" part) and it has no spam filtering.
The jewel in this is the alias file. Untrustworthy sites (most) get a specific alias.
If I get spam with that I delete the alias.