I read that 3 years ago or so someone brought this up and the canned response was that its only possible with an icewarp server. This not a very good response or stance on the subject. Being able to categorize emails is a major part of many peoples work flow with email. IMAP supports a way to do this in the RFC as thunderbird implements this exact things flawlessly that works with any imap server. The only difference is they call them “tags” instead of “categories”. Your software works great, and obviously your programmers know what they are doing, so why is such a basic needed feature not included with no desire to include it in a future version when I’m sure it wouldnt take that long for one of your programmers to include this in the net code.
In case you’re to lazy to look it up, and to prevent a canned b.s. response such as “this is not possible” - I’ve went ahead and snipped the portion of the IMAP RFC that specifies that not only that its possible, but how you would go about implementing it.
[RFC 3501](https://tools.ietf.org/html/rfc3501) IMAPv4 March 2003 [2.3.2](https://tools.ietf.org/html/rfc3501#section-2.3.2). Flags Message Attribute A list of zero or more named tokens associated with the message. A flag is set by its addition to this list, and is cleared by its removal. There are two types of flags in IMAP4rev1. A flag of either type can be permanent or session-only. A system flag is a flag name that is pre-defined in this specification. All system flags begin with "\". Certain system flags (\Deleted and \Seen) have special semantics described elsewhere. The currently-defined system flags are: \Seen Message has been read \Answered Message has been answered \Flagged Message is "flagged" for urgent/special attention \Deleted Message is "deleted" for removal by later EXPUNGE \Draft Message has not completed composition (marked as a draft). \Recent Message is "recently" arrived in this mailbox. This session is the first session to have been notified about this message; if the session is read-write, subsequent sessions will not see \Recent set for this message. This flag can not be altered by the client. If it is not possible to determine whether or not this session is the first session to be notified about a message, then that message SHOULD be considered recent. If multiple connections have the same mailbox selected simultaneously, it is undefined which of these connections will see newly-arrived messages with \Recent set and which will see it without \Recent set. A keyword is defined by the server implementation. Keywords do not begin with "\". Servers MAY permit the client to define new keywords in the mailbox (see the description of the PERMANENTFLAGS response code for more information). Crispin Standards Track [Page 11] (https://tools.ietf.org/html/rfc3501#page-12)[RFC 3501](https://tools.ietf.org/html/rfc3501) IMAPv4 March 2003 A flag can be permanent or session-only on a per-flag basis. Permanent flags are those which the client can add or remove from the message flags permanently; that is, concurrent and subsequent sessions will see any change in permanent flags. Changes to session flags are valid only in that session. Note: The \Recent system flag is a special case of a session flag. \Recent can not be used as an argument in a STORE or APPEND command, and thus can not be changed at all.