Just received this email from ProtonMail:
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:
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.
Over the past year, ProtonMail has proven to be reliable with less than 12 hours of total downtime (mostly scheduled maintenance), no incidents of permanent data loss, and no reports of user data compromise. Over that same period, the ProtonMail user community has grown from 10,000 to 500,000 people.
As you know, we respect your privacy and do not track detailed user activity. Therefore, to continue to improve ProtonMail, we need to rely on direct feedback from you and would love to hear your suggestions or criticisms in the following survey:
Many of the improvements mentioned in the survey will be coming soon. In the past few months alone, we have added new features like folders/labels, encrypted attachments, the protonmail.com domain, and more: https://blog.protonmail.ch/protonmails-new-features-guide
We look forward to continuing this exciting journey with you!
The ProtonMail Team
We believe privacy is a fundamental human right which is why we are supported by donations instead of advertisements. If you would like to support us, please visit: https://protonmail.ch/donate