A/B test subject lines on confirmation emails
Hello,
I'm trying to A/B test subj lines on confirmation emails. Does anyone know how to structure this properly?
Here's the catch, the confirmation email has been live for about 2 weeks now. Trigger campaign is anyone who fills out the form will receive the confirmation.
We just now decided to test two different subject lines.


What filter/s should I add to the smart list?

Thank you in advance.