Gmail Snooze with Apps Script

Re-Ping: Add an additional field when composing an email that causes the email you're sending to appear in your own inbox in a given number of days if there's been no reply. (It prompts you to re-ping the person if they don't respond.)

Auto-expire: Type “eN” and the message will be automatically archived in N days. This is roughly the inverse of Snooze. Alarm clocks sometimes call this a Sleep feature where you can have the radio play for a certain amount of time and then automatically turn off. Here, if you get an email about some event in a couple weeks you can say “auto-expire 14” and it will stay in your inbox for 2 weeks, and then silently, automatically go away. It’s not that it takes much more time to clean up no-longer-relevant emails from your inbox once in a while. But when you get the email is when it has your attention. If you decide to leave it in your inbox you might as well schedule the archiving you’ll have to do in a couple weeks anyway.

More about the above features (plus Snooze) here: http://messymatters.com/email

Great name.