Update smtp.markdown

Added line about adding page breaks in the email body

source/_integrations/smtp.markdown

@@ -105,7 +105,7 @@ A notify integration will be created using the name without spaces. In the above
   mode: single
 ```
 
-The optional `target` field is used to specify recipient(s) for this specific service call. When `target` field is not used, this message will be sent to default recipient(s), in this example, [email protected].
+The optional `target` field is used to specify recipient(s) for this specific service call. When `target` field is not used, this message will be sent to default recipient(s), in this example, [email protected]. It is possible to make line breaks in the message part of the email by using '\r\n', for instance 'message: "Rise and shine\r\n It's a brand new day!"'
 
 Another example attaching images stored locally in a script: