Hi Georgia,
Many thanks for this.
My background as a programmer may help here. If the search tool refreshed its index regularly, it should have stopped finding these deleted messages by now (it's been like this for months), so I'm guessing it only adds new articles to the index. In this case, when the team went through deleting messages all over the place, they should also have deleted the references to those articles in the index.
Having not done that, I think you will now need someone to go through and remove those invalid links from the index, so the search results only provide links to questions and answers that actually exist.
Please can you get an indication on the timeframe for this to happen; as I mentioned, it's very frustrating to find that potentially useful answers to a question have been intentionally deleted, and you're going to get people repeating questions without searching if we get fed up with finding non-existent search results.
