Installing the Outlook Mail App (OMA) is a very simple process. However, you will need to be logged into Microsoft Office 365 as an Administrator in order to install it.
Here are the steps:
1. Log in to Office 365 and go to Admin.
(Note: for Small Business Premium accounts, you will need to go to https://outlook.office365.com/ecp/ to get to the Exchange Admin Center.)
2. From the Office 365 Admin Center, go to Admin--> Exchange
3. From the Exchange Admin Center, go to organization and then select apps.
4. Next, click on the + to add the app and select "Add from the Office Store".
5. At the Apps for Outlook page, search for "attachedapps" to get to attachedapps for Outlook app and select it to add it.
6. At the next screen, select Yes to confirm that you want to install the app.
7. You'll then get a page that tells you that you've added the app.
8. The final step is to go back to your Exchange Admin Center to Enable the app. Simply select attachedapps from the list of Outlook apps and click on Edit. Select "Mandatory, always enabled. Users can't disable this app".
That's it! You're done and now your users have access to one of the great features of attachedContacts! The app works the same in Outlook Web App as it does on the desktop client of Outlook.
For more details about how the Outlook Mail App works, please see the article entitled "What is the Outlook Mail App and how does it work?" in this section of our support site.