Review for Export to ZIP by blobslash
Rated 3 out of 5 stars
Just like someone else already pointed out: the add-on works. Unfortunately, it doesn't tell you its status. Additionally, it seems like you cannot export a complete account's mail unless it has all mail stored in one directory. If you have more than one directory, you will have to export them one at a time. Other than that it works great.
To create your own collections, you must have a Mozilla Add-ons account.