Boomerang Gmail still rocks
I’ve been using Boomerang Gmail for a year now. It lets me schedule outgoing emails and “boomerang” emails if I haven’t gotten a response from someone. They’ve got a free trial. Use this link and you get a free spin of their wheel of free stuff when you sign up
Here are some of the things you can do with Boomerang:
1. Write messages now and schedule them to deliver at any time
2. Schedule messages to return to your inbox at a later time
3. Remind yourself to follow up on messages that don’t get a response within a certain time