Take Control of your Email
Security and privacy, mostly.
When you use Apple, GMail or Outlook.com, the company (not you) decides what security to use and how to use your private information. This matters for several reasons.
Advertisers don't worry me; they just annoy me. But lack of encryption means you don't know who is reading your email. :(
If you manage your own mailserver, you can avoid the advertisers *and* the snoops.
Rent a VPS.
A VPS at a reliable service costs $10-$15/month. Add another $10.00/year for a domain name. Everything else you need is free. Here is what you need to do:
Keep learning, and improving your skills.
It's relatively easy to learn enough about servers and the Linux operating system to set up a reasonably secure mailserver. Configuring a truly security is another matter.
If this matters, configure a computer and host it at home.
If you can't afford a VPS or don't want to bother, you can use GPG to make even GMail reasonably secure. :)