Presumably you mean a "Signature" at the end of the email.
I have assumed you are using BTMail on a browser and not with an email client/app.
Log onto your BTMail account using a browser, not an email client/app, and then click on your username at the right hand side. Select "Settings" then go to the left hand side and select "Mail". Scroll down and click on "Signatures".
Click on the signature that is showing and either edit it by clicking on the icon at the right hand side or delete it by clicking on the "Bin" icon at the right hand side then click "Save".
