Question: We have the Office 365 version of Outlook 2016. It does not seem to be possible to select multiple attachments by holding down the Ctrl or Shift keys and clicking on them. Only one attachment at a time remains selected. 

This used to work in Outlook 2013 and I think it worked in earlier versions of Office 365. How can we do this in Outlook 2016?

Answer: 
I would like to advice you it is not possible to select multiple email attachments in outlook 2016.

Instead you have to use **Attachment Tool** which is located next to File, Message option and can Save Attachments and you can also delete all attachments this option is also given in this tool

If you have further query related to this, then please let me know.
When I access my outlook account via Chrome on my mac laptop I have the option to “download” an individual file or “download all” and I get a zip file containg all the attachments.