Suddenly this morning, tired, old WLM, Version 2012 (Build 16.4.3528.0331) began once again to misbehave under Windows 10.0.19043. It receives incoming messages from three different email-provider accounts, allows composing a reply, but states emphatically "Message cannot be sent" when I hit Send. Also, most of the incoming messages refuse to delete, either with the Delete button or by dragging it to the Deleted mail folder. "Message cannot be moved" or simply "An unknown error has occurred.I love this program, but, by golly, it's sure trying to drive me nuts. Any hope for continuing to us