When I first learned that my mailbox wasn't completely secure with my old provider, I immediately sought a new one. Indeed, I do not like the feeling of having unwanted people being able to read my mails as much as they like.
A friend of mine recommended me MailFence and it was a pleasant discovery.
First of all, I have the guarantee that my mails will be read by the ones that I chose (not even them can read my mails!). Second, the extra features are actually very handy. Thanks to them, I can easily manage my messages, documents and contact in one place combined with my own personnal calendar! It is finally over, the time where I was losing so much time switching through tabs or apps!