Imports your Google contact labels and their respective email addresses, and assigns this label to all emails to which have been sent to or from them.
Inspired by the script hosted here
- goto script.google.com
- paste the contents of the GmailContactGroupLabels file into the empty Code.gs window
- review the code if you want
- save the file via the menu file+save (in your google drive)
- click "run" and authenticate the script to access gmail and your contacts
Enjoy!