Represents a defined search key for the IMAP4 SEARCH command.

TIdIMAP4SearchKey = (skAll, skAnswered, skBcc, skBefore, skBody, skCc, skDeleted, skDraft, skFlagged, skFrom, skHeader, skKeyword, skLarger, skNew, skNot, skOld, skOn, skOr, skRecent, skSeen, skSentBefore, skSentOn, skSentSince, skSince, skSmaller, skSubject, skText, skTo, skUID, skUnanswered, skUndeleted, skUndraft, skUnflagged, skUnKeyWord, skUnseen);

TIdIMAP4SearchKey is an enumerated type that represents the individual data items that can be used as search criteria when using the IMAP4 SEARCH command. TIdIMAP4SearchKey is used in TIdIMAP4SearchRec to identify the search key, and it's associated Date, Size, or Text value, to use in an IMAP4 search request.