[RFC] 5464 [Name] The IMAP METADATA Extension [Capability name] METADATA [Agorum Core] no [Apache James] no [Archive​opteryx] no [Axigen] no [Citadel] no [Communigate Pro] no [Courier] no [Cyrus] v2.5 [DBMail] no [Dovecot] v2.2.7 [GMail] no [IceWarp] yes [Isode] no [Kerio Connect] no [MDaemon] no [Microsoft Exchange] no [Oracle] v7.0.5 [UW-IMAP] no [Zimbra] no [WinGate 7] 
no