We use solely open source and licensed webmail applications, we do not currently develop any of our own. Here is the list of the webmail solutions we offer. This is subject to change as third party projects and companies are subject to changes in business model/status, vulnerabilities, abandonment, etc.

• Crossbox
• Roundcube
• Snappy (Fork of Rainloop)

One option, Crossbox, has a wealth of features which includes a selection of several webmail options that may differ from the ones we directly offer. Check out features of Crossbox here.