Developer reply by squib
Rated 5 out of 5 stars
May I translate your addon in Italian ?
This review is for a previous version of the add-on (3.0.2).You can! Just translate all the text in these files and submit a pull request on BitBucket: https://bitbucket.org/squib/mail-summaries/src/0e67c216ecf9304329588c14c48b2b6fb6e58eb3/chrome/locale/en-US/?at=default
To create your own collections, you must have a Mozilla Add-ons account.