Rated 3 out of 5 stars

An excellent idea and most useful extension, but it's probably incompatible with other extensions, as it does not appear, for instance, in my main window. Also, it would be nice if in the next update the settings (of number of days) would be available individually, for each message.
I hope that this extension will be come popular and be updated regularly, as it a good replacement of Lightning, which I'd prefer to disable.

This review is for a previous version of the add-on (0.8.8).