Also, you can buy your own domain, and have Google merely act as the SMTP relay and temporary storage. They can also forward your mail to another server for you.
It gets more difficult if you are providing a service that has to have uptime guarantees or are providing mail to many users but if you take the time to learn and educate yourself on current standards, hosting your own mail for fun and for profit is a doable thing that more developers and admins should do.
We are at a time when we actually have relatively easy to use software to managing mail servers, so us it.
For what it is worth, I have not had problems with Google, Microsoft, Yahoo, or domains that use their services whether it comes to sending or receiving. Sometimes a server is stuck in an SPAM prevention queue or I might have to whitelist a particularly silly server, but that doesn't happen very often.