I've been looking for documentation on the standard behaviour for mail servers who fail to deliver their mail. I want the 'From' field to be different from the account that receives emails when there is a delivery failure. E.g. My program sends an email from '[email protected]', and on failure to deliver I want to be sent the delivery failure bounceback at '[email protected]'. Is this accomplished by setting the reply-to? Or should I login with the 'failedemails' account and therefore it will receive the email back? Thanks.