How can i include a sign-off link at the end of the message body?

ie:

message text bla bla bla...message text bla bla bla...message text bla 
bla bla...message text bla bla bla...message text bla bla bla...message 
text bla bla bla...message text bla bla bla...message text bla bla 
bla...message text bla bla bla...message text bla bla bla...message text 
bla bla bla...message text bla bla bla...message text bla bla 
bla...message text bla bla bla...message text bla bla bla...message text 
bla bla bla...message text bla bla bla...message text bla bla 
bla...message text bla bla bla...message text bla bla bla...

If you don't want to receive this please click here.

or:

Please sign me off of this list.


Jesus Rivas