Myself and the other reviewer who elected to stay with emClient (replacing Eudora) are having consistent problems finding emails using the search function. Typically I select a keyword or a sender and I get far more messages that could possibly be correct.
I have over 20,000 unread messages (I get a lot of press releases and I have been offline for a while) with Eudora I used the search function to cull unwanted messages or find particular events.
Actually, the search function works quite well. I always use the search box with keywords. To see the available keywords, enter a “?” in the box and press enter. As an example, text:“san*” will find any word that begins with “san” (wildcards are usable). from:"*@aol.com" will find any email received from the aol domain.
One caveat-- searching while in the conversation mode showing conversations in all views can get confusing. I personally use “show conversations in message detail only”
If you give me an example of your search query and what you expect as the result, maybe I can help.