how to remove a Mail attachment before sending

I'm using Mail in Mac OS 10.14.6 (Mojave).

On more than one occasion I have added an attachment to an email I am composing in Mail, and realized before sending that I wanted to remove that attachment BEFORE sending.

I have been unable to do so, and a quick search of the 'net has not found an answer.

There is an item under the Message menu titled "Remove attachments" but that is grayed out before the message is sent. And the "undo" does not work either.

My only workaround has been to copy the text of the message and create a new message to the intended recipient(s), then paste the text back and send without the offending unwanted attachment.

Is there an easier way to do this?

TIA

Caroline