I presume you compact folders on a regular basis to help maintain a healthy file or have selected the setting in Account Setting to expunge the Inbox on exit.

There have been reported issues with Spectrum server recently (which they acknowledged), but that related to logon issues. Maybe they have other connection issues so synchronising is not fully working. If both you and your wife are experiencing the same issue from same server on different computers, I'm inclined to think this could be the server.

Have you tried the going offline and back to online without exiting Thunderbird ? In the bottom status bar, on far left, there is a two blue screen icon. You see it when you are in online mode. If you click on that icon, it will change to a two black screen icon meaning you are in offline mode. Wait a moment and Click again to return to online mode. Did this force connection to get messages?

Sorry to have taken so long to get back to a response on this one. In the meantime I did one more search on the topic of can't delete mails from the inbox and this time I found a response that said try deleting your Trash and Trash.msf files from your profile and then restart Tbird. Tried this and so far so good.

Thanks again for your initial response.