About this Add-on
From version 78, Thunderbird only supports the necessary interfaces for this add-on via "WebExtension Experiments". A lot of program code of the add-on would have to be rewritten for this. It is not expected that the necessary interfaces will be permanently implemented in Thunderbird (as MailExtension API), and the "WebExtension Experiments" will also be removed in the future, which is why the effort is no longer worthwhile. Therefore, this add-on will no longer receive an update and it will not be available for Thunderbird 78.
The source code of the add-on is open source and is available at GitLab .
The translations available so far can be found on the CrowdIn platform.
This add-on adds a simple "Send later" button to the compose window toolbar.
There are no new/own functions. The button is just a simple way to always have the send later option visible and reachable by just one click.
You can use the "Send later" button with standard Thunderbird to save your new mail in the "Outbox". In case you're using the additional add-on "Send Later" (by jikamens), the button is completely compatible with this add-on and invokes its dialog.
This add-on is compatible with jikamens "Send later" add-on.