note 10255 added to imap_setflag_full

Indeed POP3 does not support flags that indicate the "newness" of a message. There are other ways to work around this problem, though. For one, I have seen mail delivery systems that will add a header field Status: to indicate its status (see RFC2076). Another way most email clients and mail fetching programs seem to use is to keep a local list of UID's of messages that are downloaded. Upon fetching mail, the UID's of the messages can be checked against this list to see if it was already downloaded. POP3 supports a command UIDL to get a list of all UID's, but I doubt the IMAP lib uses this command. The only thing I know of that will thrash this work-around is the use of multiple mail clients. If another mail client fetches mail from the server, the first client has no way of knowing it has been downloaded. http://www.php.net/manual/function.imap-setflag-full.php