First Draft so I don't forget the process for the future.
This is the process used to import a csv that was sent to a gmail address using feeds and mailhandler. Everything is on Drupal 7
This is a rough approximation of what I did. Some things need some polishing e.g. I set it up to import even if it isn't authorized on the file import. I need to secure that.
Install PHP IMAP library (On your server)
First install Mailhandler
Install Attachment Links
Create the Gmail account you will be importing from.
Enable POP in Gmail ( I Also set it to archive messages once they were downloaded to prevent multiple imports.
Enable the modules you installed on the site.
Create the content type you are trying to import.
Create a file holder content type to hold the csv you are importing from. On the content type edit page there is a new vertical tab for attachment links, enable it for the file field. I set it hold one fiel and used the file widget.
Structure > Mailhandler Mailboxes
There is a bug currenlty when it tries to use ajax to test the settings. Fill out the domain and password last, you may have to save it and come back in a couple times. Before clicking save always click elsewhere on the page to initiate the ajax call and wait for it to complete or it won't save the settings.
For Gmail use pop as the protocol
Domain should be pop.gmail.com
port should be 995
Username is full email
Pass is stored in plaintext so use a throwaway account if possible
Extra commands must be /ssl/novalidate-cert
Create a feeds importer for grabbing the file.
Settings Standalone Form
Mailhandler IMAP stream parser
Bundle > Content type to hold the file
Update existing nodes
User for importing
Reply-to > title used as unique
attachments > file field
Feeds import form for file importer
Choose the mailbox you set up previously
Uncheck the Skip messages that fail authentication
Create importer to process the csv
Use typical settings and mappigs to suit your needs
Use the http fetcher
Use the CSV parser
Visit the node created by the file field generator and grab the newest file link [nid/attachments/newest]
Go to the http importer
Put the url from above in the url and import