Sending side of the MTA can be set up manually in about an hour on a Debian server, with dmarc, dkim, spf, etc. Make that a day if you want to read up on and understand each of the things in more detail, if you haven't configured them before. There's really not much to play with in this direction for a typical personal mail server.
Receiving side is where there is a great range of options, and many things to try and have fun with. You can have anything from a single catchall mailbox with no filtering, no GUI, and a simple IMAP or POP3 access for MUA, to a multi-account, multi-domain setup with server side filtering, database driven mailbox and alias management, proper TLS, web MUA access, etc. It can also be built up gradually, starting from very simple setup to something more complicated so that you never lose account of how things work.
Receiving side is where there is a great range of options, and many things to try and have fun with. You can have anything from a single catchall mailbox with no filtering, no GUI, and a simple IMAP or POP3 access for MUA, to a multi-account, multi-domain setup with server side filtering, database driven mailbox and alias management, proper TLS, web MUA access, etc. It can also be built up gradually, starting from very simple setup to something more complicated so that you never lose account of how things work.