Bug with duplicated messages Rated 4 out of 5 stars

This add-on is great, but there's a bug happening when I duplicate message, i.e. I copy a message to the same account. I currently do this in order to tag the message and send it to other people, through a shared IMAP account: in this case, the original message is colored although it shouldn't be. I'm not sure how to provide a screenshot which would be much clearer.

This review is for a previous version of the add-on (4.2).