Internet Message Access Protocol (IMAP) is a protocol for e-mail download & storage as an alternative to POP. IMAP, unlike POP, specifically allows multiple clients simultaneously connected to the same mailbox, different clients accessing the same mailbox at the same or different times can detect state changes made by other clients.
IMAP is supported & this feature is available free of charge on all the hosting plans. When trying to configure IMAP in you email client, the port number that you should use is 143.