gmail
After my first toying around with the new Gmail compose I clicked on the button that said 'I want to keep using the old compose' or something similar with the same meaning.
Now I want to try it again, but I don't find any option to reactivate the new Gmail compose.
How do I do it?
I've used the following tool for downloading the content of a Gmail / Google Apps mail account and restoring the emails to another account and found it works well.
You can do this if you click on the arrow at the top of the reply and select "Pop out reply"
This should open your reply into the sub-window-format compose.
Edit @justingordon asked about a keyboard shortcut for this behavior. Updating the answer.
Holding Shift+ R or A will reply (or replay-all, respectively) in a pop-out window.
Best Answer
When you deactivated the new compose feature, your Gmail should have refreshed.
To get it back, just click
Compose, and you should see a message at the top that says "Try out the new compose experience" Clicking this will refresh the page again with the new compose feature enabled.