by Jonathan Kamens (Developer) on June 16, 2016 · permalink

EDITED: The information below is unfortunately incorrect. Please see the version notes for release 5.2.1 of the add-on for a complete explanation (it's really too long to explain here).

The release notes for version 5.1 say:

>>> In a further effort to reduce confusion about the “Put In Outbox” and “Send Now” buttons in the Send Later dialog, the “Put In Outbox” button is now only visible when the dialog is popped up using “File | Send Later” or Ctrl-Shift-Enter, and the “Send Now” button is now only visible when the “‘Send’ Does ‘Send Later'” preference is enabled and the dialog is popped up using “File | Send Now” or Ctrl-Enter.

Since release 5.1, I've heard from a number of people including you whose workflows depended on both buttons being present. This is yet another example of "no good deed goes unpunished" -- often when I make a change attempting to make the add-on work better for some people, I find out too late that it makes it work worse for others, and I unfortunately don't have enough beta testers to catch these situations before they go out to everyone.

Because of these workflows of which I was unaware, I just released version 5.2 with a preference you can enable if you want the "Send Now" and "Put in Outbox" buttons both to be displayed all the time. You'll get this release automatically when the addons.mozilla.org editors approve it, or you can download and install it from https://addons.mozilla.org/en-US/thunderbird/addon/send-later-3/versions/5.2 , after which you can open the add-on preferences and check the box to bring the "Send Now" button back.

by Jonathan Kamens (Developer) on June 2, 2016 · permalink

For the record, the natural language recognition in Send Later is part of a third-party library, SugarJS, written by Andrew Plummer. So he gets the credit for that. :-)