Cypht can be used with any standard mail server. In the context of WikiSuite, Virtualmin provides standard email accounts.
Here is the source code: https://github.com/cypht-org/cypht
Cypht is available as a standalone webmail client, and within Tiki, it gets additional features like calendaring (ex.: CalDAV). And over time, it will become feature-rich, as is the nature of Tiki's community and development model: Tiki is the Free / Libre / Open Source (FLOSS) Web application with the most built-in features. Please see https://dev.tiki.org/Email-as-a-first-class-citizen
Cypht has what you'd expect from a webmail client, and some very interesting features like aggregating email from multiple accounts.
Here is how Cypht is different: Webmail and groupware comparison
- Combined inbox, unread, sent, and flagged message views for all your E-mail accounts (and RSS feeds), as well as standard E-mail client folder navigation
- Flexible profiles to combined IMAP accounts with SMTP accounts and setup signatures and reply to details
- Compose messages in plain text, HTML, or Markdown (markdown formatted messages are converted to HTML before being sent)
- Search all your E-mail accounts and RSS feeds at once with a simple form
- Simple interface translation system that does not use gettext or .po files, just arrays of translated strings defined in PHP. Right to left languages are supported.
- Module sets for IMAP, SMTP, LDAP or local contacts, WordPress, Github, and lots more! Check out the Modules page for a complete list.
- Sessions and user data can be stored in any PDO compatible database or flat files on the server
- Authentication is flexible and currently supports IMAP, LDAP, an included database schema, dynamic authentication using popular E-mail providers, auto-discovery based on the user's E-mail domain, or you can roll your own with the site module set
- Sessions and Authentication can be customized without breaking any modules using the site module set
- Why Cyrus IMAP and Cypht
- Cypht has started adding support for JMAP: https://unencumberedbyfacts.com/2019/01/24/jmap-its-like-imap-but-not-really/