Do you mean the text you get in the body of the message when sending an invoice, order, statement, etc to email? If so edit your layout and go to Report -> Email Settings. There you will see an option titled 'Send the report as an attachment, with the following message body'. Simply enter the desired text in the box below this, click OK and save your layout.

Hope that helps.

Thank you Darron.  This is exactly what I am looking for