The imap_delete function allows the option to use a UID for the message number but the imap_undelete function does not.
(PHP 4, PHP 5, PHP 7, PHP 8)
imap_undelete — Unmark the message which is marked deleted
$imap
, string $message_num
, int $flags
= 0): boolRemoves the deletion flag for a specified message, which is set by imap_delete() or imap_mail_move().
Returns true
on success or false
on failure.
The imap_delete function allows the option to use a UID for the message number but the imap_undelete function does not.