With the following preferences: - mark message as read when selected after 2 seconds; - after checking for new mail go to inbox; - show receive dialog only on manual receiving; - notification icon in tray, minimise to tray, close to tray; - Claws window closed and icon visible in the tray. If I receive an email automatically, the tray indicates new mail and stays that way. If I receive new mail when checking manually, I get the dialog and then the icon shows new mail. However, if I am in a different folder to the one receiving mail, then receive mail manually while Claws is minimised, the dialog shows, the icons indicates new mail, then the icon goes back to nomail. On opening Claws, the current folder has changed to the one that received the message. If the receive dialog is not displayed this doesn't happen. So the receive dialog is counted as Claws being open and so the message gets selected and then marked as read?
Re-reading this, I can see it might be a little confusing just what the bug is. To summarise, it is possible for new mail to arrive while the main window is closed, but the tray icon will show no mail.
Do you have the option set to go to inbox after receiving new mail? (/Mail handling/Receiving page). On the /Display/Summaries page of the prefs, for the 'Set default selection when entering a folder', 'Selection of folder opening' set to 'First new mail'? Also on the /Display/Summaries page, do you have the 'Open message when selected' option set to 'Always'?
"Go to inbox" is set. "First new email" is the first selection for "Set default selection". "Open message when selected" is set to "Always". Also, "Mark message as read" is set to "on selected", after 2 seconds. With this combination, I expect that a newly received mail message will be selected, and shortly afterwards marked read, when it arrives with the Claws main window open (although that doesn't happen if the relevant inbox is already selected), which is fine. I expect it not to happen when the main window is closed, or at least not to happen until I open the window. Which is also fine. The tricky case is when the main window is closed and the receive dialog visible, then the message still gets marked read even though I have no hope of ever having seen it.
You have plenty of choices and I think you can see how your choices are the cause of the behaviour you describe. What you describe is not a bug. You are actually asking for another option. I'll close this, but feel free to open a new item as an 'enhancement'.
Yes, my choice of preference settings cause a bug to happen. Bad me ;)
Not a bug - it's doing exactly what the settings you chose are intended to do.