I used postfix and dovecot as well.

Basically walked through Linuxbabe's excellent guide and was done in about 1.5 hours with SPF/DKIM/DMARC.

https://www.linuxbabe.com/mail-server/build-email-server-from-scratch-debian-postfix-smtp

I have my own domain and a static IP with one of Linode's nanode sizes servers for USD5 a month, works pretty good.

IMO the only truly difficult part of self hosting is mail delivery because you end up at the mercy of big stupid companies (eg Microsoft) that don't give a shit. It is possible and possibly advisable to use a paid service for delivery and let someone else deal with the bastards.

With a bit of research and a methodical approach I think just about anybody comfortable setting up other linux network services should be fine. I am very lazy and have been doing it for 2 decades. I like being in control of my own mail store. I choose to do my own delivery and the only persistently difficult provider is Microsoft's free email offerings which I care about about as much as they care about running a reliable mail system for their users. They seem to penalize infrequent low volume senders. I have always been signed up to their spam monitoring bullshit and have never had a negative report but they don't seem to communicate there so you can be blocked and nobody knows how or why. They blocked most of my hosting provider once so I routed my outgoing email with correct dkim, spf etc from a server hosted elsewhere. Easy to do with Postfix.