Okay, we caught a fish! I approached my computer to find five new messages that I considered spam but which SpamSieve had not moved out of the inbox. I selected them and chose Train as Spam; SpamSieve’s icon turned a sort of pale pinkish and nothing happened. I captured a diagnostic for SS and also samples for Mail, SS, and the plug-in. [Attached.] Eventually (30 seconds?), SpamSieve’s icon turned its normal black, and I tried the same selection and command again, and again nothing happened. I then quit SpamSieve; eventually it relaunched and I tried again, and this time, after a pause, the move succeeded.
Hope this is useful somehow!
Archive.zip (455.1 KB)