Swift Mailer
Handling Undeliverable Emails
How do you know if an email gets there or not? Quite often you don't! To remedy this, Swift Mailer adds a new field to your Edit Email Templates page, allowing you to specify the email's "return-path" header. This option ensures that all undeliverable emails get bounced back to a specific email address rather than just get lost in the tubes of the internets.
Take a look at the screenshot to the right. When you have Swift Mailer installed you'll see the final "Undeliverable Email Recipient" field. This field does NOT appear if the Swift Mailer module isn't installed.