Rated 5 out of 5 stars

Works fine. If you change the "Shortcut" delay time to a custom value (15 min -> 5 min e.g.), the message is organized to be send at the right time (send time + 5 mins) but at the compose message window you see unchanged value (125 min). Could it be adjusted? Good jod, thanks!

This review is for a previous version of the add-on (3.3.10). 

The same place that lets you edit the shortcut delay times (in the preferences) also allows you to edit the shortcut labels. The default label, "<from locale>", only works for the default values.