I also have a small domain that is relatively low traffic. A lot of the “all in one” software on the list you linked looks pretty cool, I can’t deny.
What I found is that I make very few changes. I used to add mailbox aliases fairly often, but the fact is there are only two users and enabling the “+” syntax in addresses put a stop to me needing to make new aliases when I wanted a new address.
I just don’t feel like I need a management interface. Because of this I’ve just sort of frankensteined my own setup together and I love it. It operates how I expect it to, and enforces the standards I care about to the extent that I desire (e.g. which SPF result codes am I ok accepting?).
Postfix as SMTP/Submission server. I chose to go w/PAM based for outbound SMTP auth.