If that is your email address and you like to receive a lot of spam, leave it there.
If you do not like to receive spam it is never a good idea to post your email address on a public webboard.
The message is saying that avast scanned the mail, nothing more nothing less.
So what is the problem ?
If as I suspect you are trying to remove that message at the bottom of the email.
avastUI > Settings > Active Protection > Mail Shield - Customisation > Behavior and uncheck the option to insert note into clean message.