Phantom email sent

Hello, twice recently I have sent an email and for some reason a second email was sent having no content in the body. The recipient received my email, and the phantom email also resides in my Sent folder. My account and the recipient were both on gmail. Any explanation that you can share? This problem cannot be replicated. Thanks!

Hi, have same problem after upgrade to 9.1.x
some from the user produces Phantom Email wenn sending email.
We are using Emclient with onPremise Exchange.