I am looking to migrate my personal mail to a free service that has reasonable storage space, supports IMAP, and is headquartered in the EU. So far GMX.com is the only one that fits the bill, but the free tier benefits are a bit too generous. Is there a catch?
If the service is free, then you are the product. Just pay for mail. Someone here mentioned Posteo. I use Soverin.net. It costs peanuts. Also, make sure you get your own domain name. It makes migrating email to a different provider trivial. It’s really worth the 10 or so Euro per year.