The format of the virtusertable is:
Pretty basic stuff. Tab or whitespace delimited, and the firstname.lastname@example.org must be unique within the file.
At some point in the past, many of these 1,000 people were entered with invalid forwarding addresses. It never caused any problems, because no one ever sent email to the addresses. So, some of the entries were good (aka unique), and some bad (aka duplicative)..
I hacked together a quick group of scripts to add the unique entries, remove the duplicates, etc. However, today I discovered that although I had removed the duplicates, I hadn't replaced the duplicates.
So, it looks like I get to walk through the code again tomorrow. *sigh* This is why I despise quick hacks. They always take more time than doing The Right Thing.
Sometimes I'm just too smart for my own good. No, that's very incorrect. Sometimes I think I'm smart enough to neglect history. As it's been said (by Dave Barry, I believe):
There's a lot we should be able to learn from history. And yet history proves that we never do. In fact, the main lesson of history is that we never learn the lessons of history. This makes us look so stupid that few people care to read it. They'd rather not be reminded. Any good history book is mainly just a long list of mistakes, complete with names and dates. It's very embarrassing.