NOTE: You will need access to System>tools>Quick messages in order to do this
Go to System>Tools>Quickmessages tab
Choose New and choose email quickmessage and click Okay
Choose a suitable name for the new message that will be clear to you and your colleagues (eg 'exchange')
Type the contents of your message and Save when done
The new standard paragraph will be available in the Quickmessage dropdown box when creating an email