In the attached screenshot, which setting corresponds to SSL/TLS? Sorry to ask such a basic question, but my Help file has disappeared again

Both the "Via STLS command" or "Via direct SSL connect" do. The difference is that the "Via STLS command" option sends a command asking the server whether it supports an encrypted conversation whereas the "Via direct SSL connect" option assumes it does. Use the "Via direct SSL connect" option if the host specifies "SSL/TLS".

The port number is important. Pegasus Mail may ask you if you want change the port number so be attentive to that and stick with the one specified by the host. It could be 465 or 587.

Think the Help issue is in STATE.PMJ
Line should be something like this from mine.
PMHELP5=0,0,0,0,"196 117 854 600 272"

copy STATE.PMJ to backup.
With Pegasus closed, could just change it to
PMHELP5=0,0,0,0

Then open Pegasus. and try help.
If doesn't fix, can just copy backup to STATE.PMJ.

Had to look, but think that was the issue in past.
Gets set to a value that doesn't display.
Hope that helps.

Sorry Tom, I missed the missing Help comment. @msetzerii is correct about the PMHELP5= entry in STATE.PMJ. You don't need to change it values though, you can simply remove the PMHELP5= entry. The next time the Help system is called it will open in its default location and size.

Edit: If you are hesitant about editing STATE.PMJ, here are the steps for bringing an off-screen Help system window on-screen in Windows 11.

• Hover over the "Pegasus Mail Help System" entry in the Taskbar.
• Right-click in the window preview that appears (hopefully you don't have this disabled in Win11), select the "Move" option.
• Move your cursor away from the taskbar and notice that it has turned into a cross with arrows on all ends.
• Tap one of your keyboard arrow keys and notice your cursor return to normal.
• On movement you will see that you are dragging a minimized Help system window.
• Left-click to drop the minimized window.
• Grabs its corners to stretch it to the desired size. Position it as desired.

Thanks to @msetzerii and @Brian Fluet. You're both stars! I deleted the line (wasn't sure what to open it with but used Word) and I now have a Help File! What makes it disappear?

Just for info - the Zen port is 995

Closing Pegasus Mail while the Help system is minimized will do it. Subsequent attempts to open it results in it opening minimized at what I believe is a screen location behind the taskbar. I believe this based on how the preview>move procedure works.