This site will explain why you should protect your own mail.
Securing your mail is like securing your house. All house doors have a lock, only the owners have a key
Securing your mail works the same way. You give your address and lock, but keep the key to yourself!
Potential issues with secure mail providers
How do you know for sure their locks and keys are good enough?
Avoid security by Obscurity!
Can you trust the suppplier? What if he is bought by another company?
What if their server gets hacked and messages and keys are stolen?
No one in the middle
Only sender and receiver can read the message
Open standard encryption makes use of the best available. Otherwise it will be in the news soon!
Just a public and a private key
To send an email secure you need a public key from the receiver.
The recieve an secure email you need a public key for your address and a private key (only for you!) to decrypt the message
1. Get a public / private key
2. Activate encryption in your mail server (Apple see ..., Gmail see....,.xxmail see ... )
3. Just send the mail