The Process Path - relates to HxTsr.exe, a program developed by Microsoft. It is also a part of Microsoft Office 2016.
- I don't use any MS email program/s so I have no personal experience of that.
However, a search for the HxTsr.exe file name returns many hits -
https://www.google.co.uk/search?q=HxTsr.exe&ie=utf-8&oe=utf-8 - check out that search and if you are using any of the programs legitimately listed then it would appear to be an email it is trying to download. That said there are lots of hits indicating it could be malicious.
Now your screenshot indicates it has been sent to Quarantine, if you Open the Quarantine it should indicate what has been sent an email or the HxTsr.exe file ?