What does the add-in do?
It allows people to add files from cloud storage providers (ex: Dropbox) as attachments to their e-mails.
Where do people download the add-in?
It's developed as an Office Web add-in. People either browse it on Office Store or download it from their Outlook.com / Outook mail clients. (Images below to show the flow)
How does it use Dropbox API?
It accesses user's files through OAuth and using Office.JS attaches them to the email. No permissions are changed on the items.
Does it have a dedicated website?
It's support and privacy documentation are hosted on oattach.armhil.io and the actual web add-in is running on heroku. It currently uses the Office Store page as the main page. It doesn't have a dedicated website since you can only download it from Office Add-in Store.
An email test account as well as a Dropbox account should have been provided to you as part of the submission. If the email sign-in doesn't work (given that this is an e-mail add-in and
due to location security checks sign-in might have problems) any outlook.com account should have this functionality. There are detailed instructions below for installing
After signing in using the outlook.com account details that was provided, you can follow these steps to test the addin.
Please note that this is not a requirement as long as you're using an account that was provided to you. If the account doesn't work, the regular installation steps would work for you just fine. For Dropbox official review, you should have been provided with a test account. See further details below.