We need to be able to run mail merges through Outlook on the web, just like on the desktop app, so that we can use this functionality when working away from the office.
This is a significant omission in the online toolset for Office 365. The desktop apps can do this using mail merge on Word, which works fine, but it's not possible to do this with the online tools, which has a knock on effect on risk management for sensitive user data.
Tony Lewis commented
I need this functionality too! I needed to send 200 emails using OWA which would have been easier and better with mail merge. I was able to do a work-around by importing the emails into a contact list and creating a template in OWA, but that is not an ideal solution. I work for a government agency where I only have access to OWA. Please provide an update on this request.