You can also use the Envelope Preference section to say how any of your mail that is undeliverable is managed. 

The options are:

Not managed - Any mail that is undeliverable by Royal Mail is returned to our site. Returns are disposed of securely at our site and you will not be notified- this is included in the price.

Managed - Any mail that is undeliverable by Royal Mail is returned to our site. Returns are recorded against your Docmail account with Royal Mail’s reason for their return, before they are disposed of securely. This allows you to see which addresses have mail that has come back and the reason, so that you can update your data lists accordingly.

Use own return address - Any mail that is undeliverable by Royal Mail is returned to the address that you specify, allowing you to process your own returns.

Additional charges are incurred for dealing with managed returns. Please see our price list for more information. The following return options and envelope combinations are available: