The Sender Policy Framework (SPF) is an open standard used by email systems to verify that the computer sending an email is authorized to do so. Updating your domains (e.g. snarfcorp.com) SPF record authorizes the Digital Pigeon app to send emails on your behalf which improves branding and delivery.
By default when the Digital Pigeon app sends out notifications to your recipients (for example, to let them know files are available) it does so through the email.digitalpigeon.com mail servers. That means that emails have a 'From' address of 'email@example.com' and a reply-to address of your own email address (e.g. firstname.lastname@example.org).
With the SPF record configured any mention of the 'email@example.com' email address is removed which improves your branding. The biggest benefit is that the receiving mail server can have more confidence that the email is legitimately from you, which greatly lessens the chance that it accidentally ends up in their spam folder.
Setting up your SPF record
See the documentation provided by your DNS hosting provider (it differs from one to another). It should be as simple as adding 'include:email.digitalpigeon.com' to your DNS SPF record. To verify that Digital Pigeon has detected the update head to 'Manage' -> 'Email' and look for a success message at the top of the page.
Note: stuffing up your SPF record can lead to some pretty annoying problems with email delivery, best to get your IT person to do it...