$nntp->newnews(since[,groups[,distributions]])
Returns a reference to a list containing the message-ids of all news posted after since, that are in newsgroups matching groups, with a distribution that matches distributions. Arguments are:
Time value; only groups created after this time should be returned.
Optional group pattern or reference to a list of group patterns indicating which groups should be checked for new messages.
Optional distribution pattern or reference to a list of distribution patterns. If present, only groups matching a specified distribution area should be returned.