[helmchenlord]

Any VPS that is capable of tunneling SMTP/IMAP ports to your home machine is also capable of simply being your mail server.

Source: Me running mail servers on VPS since they've existed.

[akho]

Absolutely. Grandparent comment was about running a server at home.

(Among other capabilities, a VPS is capable of being read by your hosting provider or whoever can get them to give access)