(PHP 4, PHP 5, PHP 7)
imap_uid — This function returns the UID for the given message sequence number
$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().
The UID of the given message.
Note:
This function is not supported by POP3 mailboxes.