If you just want to send mail to yourself, the most reliable way might be just connect to your own mail server via port 25 and send the mail that way. It would fail on a system that was only online periodically, but would succeed on any permanently connected system.

It sounds like you want your program to send mail to you without the user knowing it. That's not a good way to get users of your software to trust you. You might find it preferable and more reliable to just include a request to mail you in the program's documentation, or request permission before sending the mail, at which point you can ask the user about their mail system.