(PHP 3>= 3.0.3, PHP 4 >= 4.0.0)
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.