reading/parsing mbox file

Is it possible to open and read a local mbox mailbox file using PHP? I know that it is only a text file, and I can parse it myself using regular expressions etc., but are there any functions or libraries to make it easier? IMAP would seem like the obvious choice - I've used it before and it has the sort of functions I need (get message header/body/structure/etc.), but this only seems able to be able to communicate with a local mail server, not to read a local file directly. Is it possible to get the IMAP functions to open and read a local mbox file, and if they can't, is there any alternative set of functions that will do the job, or has anyone already written a set of regular expressions to parse the text file directly? In case it makes any difference, I am working on Mac OSX (Jaguar), trying to read mbox files exported from Entourage. Thanks in advance, Andy Clarke