Just received this offer from Proton mail based in Switzerland who claim to be one of the most secure free email providers around. You will need 2 passwords to access the email account:

Hi Everyone,

Thank you for using ProtonMail!

To celebrate our 1 year anniversary, we are upgrading all accounts created by June 17th, 2015 to 1GB of free storage! Many of you have also asked for a way to share ProtonMail with friends and family. To do that, we have created a special link that allows instant account creation:
https://protonmail.ch/privacyforall

You can send this link to friends and family and they will be able to get a ProtonMail account instantly. As our server capacity is still limited, we will only keep this link active until June 17th, 2015 (or until we hit capacity limit). Also after June 17th, all new accounts will default to 500MB of free storage.