POP - deleted from trash

I use the free version 6.0.22344.0 as POP, on Windows 8.1.  I often search for deleted messages but they seem to have been ejected from the Trash folder.  I think that this happens when I delete another message with the same subject.  Is this what is supposed to happen, and if so, can I prevent a message deleted to Trash from itself getting rid of previous similar messages?

Hello Roger, eM client does not remove messages from the Trash based on the subject of the message. However make sure you have your POP3 account setup based on your personal preferences as the default POP3 settings may be setup to remove items from your Trash folder after a selected number of days.

Go to Tools > Accounts > Your account > POP3 and adjust the “Server settings” option.

Hope this helps.