How to install IMAP on ClearOS

yum install app-imap

And visit https://example.org:81/app/imap to configure

This installs Cyrus IMAP. You likely also want to: install SMTP

This provides a standard IMAP server. And thus, the Cypht client in Tiki can be used as a webmail

Some operating systems offer a built-in IMAP client. If yours doesn't or you want something more powerful, here are some options:

• https://f-droid.org/packages/com.fsck.k9/ (Android)
• http://www.claws-mail.org multi-platform

In the ClearOS admin panel, you can determine which users have access. Adding a new user with IMAP enabled does not automatically create the mailbox. The things that trigger this are:

• for successful login events,
• for email messages that arrive for a user
  • Can be done with

    $ mail -s "This is the subject" somebody@example.com <<< 'This is the message'

• when a Sieve script uses the “fileinto” action.

See also:

• Cyrus IMAP 3 and JMAP development
• Cypht