SenderID is an email technology primarily promoted by Microsoft that minimizes phishing attacks and ensures that permission-based email marketing emails get delivered.

This is based off of the Sender Policy Framework (SPF).

SenderID works by specifying which mail servers are allowed to send mail for a given domain name. The application has this setup, however, only mail that is sent with Reply Tracking enabled will be able to be fully verified. This is because Reply Tracking messages have a from name with the same domain as the sending mail server.