RFC 3503:Message Disposition Notification (MDN) pr...
RFC-Ref

IMAP4


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... set". Thus, using \Recent as an indicator will cause unpredictable client behavior with different IMAP4 servers. However, the client MAY use \Seen flag as one of the indicators ...


... Myers, J., "IMAP4 ACL extension", RFC 2086prop(-> 4314prop), January 1997. ...



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