A step-by-step walkthrough of an Auto Run campaign that chases unpaid invoices daily without ever emailing the same client twice.
Start with a sheet that has Client, Email, Invoice, Amount, Due Date and Status columns. Status is the column that drives everything.
Write the campaign
Open Mailvern from the Extensions menu, add the condition Status = Unpaid, and write your reminder using {{Client}}, {{Invoice}} and {{Amount}} placeholders.
Turn on Auto Run
Turn on Auto Run daily and duplicate protection. From then on, a client is reminded once when the invoice becomes unpaid — and never again by accident.