As in depth as your setup is, I'll take a stab:
If you feel comfortable using your existing mail service (if you have one, likely through your ISP) then you can simply send/recieve email as you probably already do via pop3 or IMAP. However, if you are allowed by your ISP to host your own mail server, and feel that it would also be better for your situation to control mail delivery locally, then you will want to setup your own mail server.
Mail server = Local mail delivery/reciept control
Mail Client (without local mail server) = Ability to send/recieve email via existing protocols such as POP3 or IMAP through an established email account with an external source (for example, if your ISP is verizon, then something like: firstname.lastname@example.org
would be the email address you have).
It's always nice for learning experience to setup a mail server, however, if you don't have the desire or time to learn, then it's really not necessary. You can accomplish your goal with something like a cron job or the likes.