It's easy for someone to spoof an email. That is, send an email pretending to be from somebody else. To combat spoofing, Applaud supports DKIM (Domain Keys Identified Mail) authentication, where you can sign Applaud outbound emails digitally to prove they came from within your organization and not somebody pretending to be from your organization.
Your email service provider can check inbound emails to see whether they're signed and if the signature is associated with your organization's registered domain name. If the message is signed correctly, your email service provider delivers the message as usual. However, if the message is not signed or is improperly signed, your email service provider can deliver it with caution to the user or discard it.