imap_uid(PHP 4, PHP 5) imap_uid — This function returns the UID for the given message sequence number Описание
   int imap_uid
    ( resource $imap_stream
   , int $msg_number
   ) 
  This function returns the UID for the given message sequence number. An UID is a unique identifier that will not change over time while a message sequence number may change whenever the content of the mailbox changes. This function is the inverse of imap_msgno(). Возвращаемые значенияThe UID of the given message. Примечания
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