What is the role of preview text as “second subject line”?

Preview text functions as a second subject line because it's the next thing recipients see after the subject-additional space to convince them to open. Together, subject and preview text form a combined pitch of 100-150 characters in most inbox views.

Strategic uses: Extend the hook (subject teases, preview delivers context), add urgency (subject states offer, preview adds deadline), provide specifics (subject is broad, preview adds details), or include a secondary CTA. The preview can also contradict or subvert expectations for intrigue.

Two lines, one goal: the open. Don't repeat your subject. That uwastes the extra space. Don't let it default to \"View in browser\"-that's negligent. Craft preview text as deliberately as your subject line. Test subject+preview combinations together. Some subjects work better with certain preview approaches. Find your winning pairs.