Save to files instead of attachments
Whilst chatter feed functionality has been around for a long time, as per Ryan's comment here: http://ideas.cirrusinsight.com/forums/121921-general/suggestions/7204809-save-gmail-attachments-to-sf-files
This is not in line with the current salesforce roadmap. This action saves the files to attachments, a feature that is being sunsetted by salesforce, and will not be migrated into lighting.
It is necessary for admins to be able to determine which related list we push emailed attachments to, so that we can enable users effectively.