Rated 5 out of 5 stars

It simply sends emails later! When you click "send later" it pops up a dialogue with half a dozen preset options to choose from eg "send in 30 minutes" "send in 2 hours", or the option to specify the exact time (to the second!) you'd like the email sent. It relys on Thunderbird running at the moment the send is required, but it's not daft - if it misses a scheduled send, it simply sends your email at the first chance it gets, the next time Thunderbird is run. Great little add-on.

This review is for a previous version of the add-on (5.0.1).