have been running my own mail server(s) since early 2000. If Hillary can, you can :)

but of course there are downsides as well, you need to expose services from the outside, you need to allow SNMP inbound, you need to deal with DNS and various mail security enhancements, deal with anti-spam and do mailware/virus scanning etc. on top of that you would need to consider some kind of “high” availability. if your server goes down = no emails…

for me its worth it, my exchange server have been running for the last 10 years or so, I publish both webmail and use the outlook and/or mail in my phone.

I have multiple domain (10+) and run my own DNS.

The only thing I can’t do is send emails… I have to rely on my ISP for outgoing emails, but that’s a good thing as generally my emails are not marked as spam as they comes from a trusted source.