>Ny pint is , that is display option not the filter condition. I just want it to do what it says it does, show the first message in the threads picked up by filter conditions.

If the type of results is All, then you end up with a specific amount of messages. Lets say 100. Then, if you add additional filters, the only think it could give would be less messages. So, for example, we could end up with 86. That's how those filters work. The more we add, more messages would be filtered from the result in the calendar as per the previous searches. So, as I said, if I have 100 messages where the From is from me, it would mean that adding the mentioned filter would give less messages, which would then be only those first messages from threads where the From is from me. The explanation of the type of search in regards to "Only the first message of the thread" is clear to me. I really do not see how I could rephrase that one to make it more clear. To my understand, it seems you would like to alter the behavior of the option once you obtain the initial result. If that is the case, as I said, then we could add an additional filter in the list for the Type of results.