def matches_p(sender, nonmembers, listname):
    # First strip out all the regular expressions and listnames
    plainaddrs = [addr for addr in nonmembers if not (addr.startswith('^')
                                                 or addr.startswith('@'))]
    addrdict = Utils.List2Dict(plainaddrs, foldcase=1)
    if addrdict.has_key(sender):
        return 1
    # Now do the regular expression matches
    for are in nonmembers:
        if are.startswith('^'):
            try:
                cre = re.compile(are, re.IGNORECASE)
            except re.error:
                continue
            if cre.search(sender):
                return 1
        elif are.startswith('@'):
            # XXX Needs to be reviewed for list@domain names.
            try:
                if are[1:] == listname:
                    # don't reference your own list
                    syslog('error',
                        '*_these_nonmembers in %s references own list',
                        listname)
                else:
                    mother = MailList(are[1:], lock=0)
                    if mother.isMember(sender):
                        return 1
            except Errors.MMUnknownListError:
                syslog('error',
                  '*_these_nonmembers in %s references non-existent list %s',
                  listname, are[1:])
    return 0