Solution 1: Press Alt or F10
In some cases, the Send and Attach buttons in Thunderbird may disappear if the toolbar they are located on is somehow hidden. If that is the case, simply pressing Alt or F10 when you are in a Compose Message or Reply window will unhide all hidden toolbars. If pressing Alt or F10 doesn’t work for you, don’t give up hope and simply move onto the next solution.
Solution 2: Enable the Composition Toolbar
Your Send and Attach buttons may not be where they always are because the entire Composition toolbar (known as the Mail toolbar in older versions of Thunderbird) has been disabled. If that is the case, simply enabling the toolbar that has been disabled will cause your Send and Attach buttons to be restored. Click on View in the top left corner of the screen. Click on Toolbars.
Make sure that the Menu bar, the Composition toolbar, the Formatting bar and the Status bar are all enabled. If one of these toolbars isn’t enabled, enable it. Save the changes and check to see if the Send and Attach buttons have been restored to their original positions.
Solution 3: Restore the default button set on your Composition Toolbar
If all of the toolbars in View > Toolbars are visible but you still can’t see the Send and/or Attach buttons they may have somehow been moved out of their respective toolbar. To restore them, all you need to do is restore the default button set for the toolbar on which they are located – the Composition (or Mail) toolbar. Click on View in the top left corner of the screen. Click on Toolbars. Click on Customize. Click on Restore default set. This will restore all toolbar layouts to their default configurations.
Solution 4: Reset Thunderbird
Resetting Thunderbird will not result in loss of e-mails, only the view and toolbars will be resetted. To do this, Hold the Shift Key and click on the Thunderbird icon. Then put a check in, Reset toolbars and controls, and choose Makes Changes and Restart.
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