imap_uid

(PHP 3>= 3.0.3, PHP 4 >= 4.0b1)

imap_uid --  This function returns the UID for the given message sequence number

Description

int imap_uid (int imap_stream, int msgno)

This function returns the UID for the given message sequence number. An UID is an 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().

Note: This is not supported by POP3 mailboxes.