I've just started using the imap_sort function, and I notice that sorts by
subject exclude "Re:" and "Fwd:", and sorts by 'from' seem to sort strictly
by the email address, excluding any name portion (e.g. 
John Smith <zz@foo.org> would be sorted by zz@foo.org).  Would it be possible to include a flag to sort without any interpretation of headers?

Here's how I'm doing my sorts, if it matters:

$msg_array = imap_sort($config_obj->imap_stream, SORTSUBJECT, 0,
                SE_NOPREFETCH | SE_UID);