An “hidden” feature in Thunderbird, makes the email client queue the message and send it in the background, one of the neat Outlook functionalities I’ve been missing since I switched to Thunderbird years ago.
The “send in background” capability is not exposed in the preferences (at least as of TB 3.1.1) — to enable the it, go into Preferences -> Advanced -> General -> Config Editor, change
true and restart Thunderbird.
According to the Mozilla Wiki:
The following parts are implemented:
- Basic send in background.
- Sending a message will temporarily (for about a second) put it in the Outbox in Local Folders, and then Thunderbird will attempt to send it.
- Activity Manager progress and notifications
- The activity manager will echo progress and notifications of sending messages in the background (or via Send Later).
- Partial shut down support.
- Sending a message and attempting to quit should bring up a dialog which is retained until the message is sent. On Windows and Linux this will only happen if File -> Quit is used not the ‘x’ on the window.
- If there is an error, Thunderbird won’t attempt to automatically send the message a second time (until another message is sent).
- If there are multiple messages queued, Thunderbird won’t attempt to automatically send other messages that are queued.
- Thunderbird won’t notify the user if messages are being sent during shutdown.