Install the add-in via the ‘Manage add-ins’ setting of your Office 365 web interface by pasting the URL for the Davton-Subscribe manifest file.
1. In your on-line Outlook account, select the Settings menu and choose ‘Manage add-ins’.
2. Select the + (add) option and choose ‘Add from a URL’.
3. Paste in the URL for the Davton-Subscribe manifest file. The URL is:
4. At the warning – select ‘Install’.
5. That is it - you have added the Davton-Subscribe add-in to your Office 365 account.
It will now work in all Outlook clients connected to your Office 365 account including Outlook Web App, and Outlook 2013/2016 (but not Outlook 2010 or lower).