Use Custom Tracker Domains in Email Links and Vanity URLs
Tailor your email links and vanity URLs for your message. You no longer have to use your primary domain for link rewriting or vanity URLs. Assign any of your tracker domains to email templates for link rewriting, and create vanity URLs using any of your tracker domains.
Where: This change applies to all Pardot editions.
When: This feature will be available in all accounts by mid-April.