Forked from : https://gist.github.com/soxofaan/92fab6776c1bfcac060544ba0c9dd59c
- Think of a deletion scheme and create GMail labels accordingly I use a three part label, parent label is "autodelete", next level is number of days, third level is descriptive. (e.g. I have labels like "autodelete/7/facebook" and "autodelete/15/linkedin")
- set up filters in GMail to flag desired mails with these labels
- create a Google Apps Script with this script (adapt function names, labels and day offsets appropriatedly) and set up triggers as desired
- I also star messages to prevent autodeletion.