One option would be to set up a micro VM at AWS, or Digital Ocean, etc. to host your mail server, with something like Squirrel Mail. Then set up your gmail account to allow forwarding for your other email address ("send mail as" in Settings / Accounts and Import), so that outbound mail from your private server can be forwarded through Google's servers (so you don't get blocked by everyone else).

This way, if Google mail goes away, you can pick up another free email provider to relay mail through in the future (assuming everyone else also allows "send mail as").