Just use established, well-run, professional email services. $1 would get you 1 POP account with 10GB space and unlimited Aliases with support (not to mention spam free servers, no downtime because they have hundreds of servers etc.) and spam protection that is a bit better than Gmail's
No need to build your own. Just don't expect Ocean basket to have the best steak on earth. Separate your services. Hosting websites? Use a host that specializes in HOSTING WEBSITES (and doesn't have other services like ADSL/Wifi and *** like that). Want email? Use an email provider that does just that (or email, very very well and not the CPanel bull****). Want internet? Use an ISP that supplies that for you. But again, don't go to Thailand and search for Ms Right and be surprised her penis is bigger than yours.