Thought you said you'd found it (Message 76 above).
Good news! What was it?
Another, & hopefully my last point about Thunderbird.
Is it safe, from a security viewpoint to leave the T/bird Icon in the bottom bar rather than open every time from the Desktop?
Yes it is safe. It only connects to the server when you open the program or if you click the send receive button. If you do leave it minimised in the task bar you will need to click the send/receive button when you open it which will refresh and fetch any new emails.