I have been trying in the past to do this myself but I stopped for the following reasons:

• what happens if your internet connection is lost while someone sends you an email? It probably will not reach your mailbox. If you host it on a private internet connection, it might drop now and then (ISP updates your modem at night, you need to turn off the electricity, etc)
• its complicated.
• mail is crucial for me. It needs to be 100% reliable.

I ended up buying a domain name and hooking it up to a premium email service (fastmail, but there are plenty others).