Set up automated dispatch of supplier invoices with e-signature

We run accounts payable through an accounting system that already stores our supplier invoices, but every document still gets pulled out, signed and emailed by hand. We want to replace that manual routine with an automated pipeline: the invoice is generated inside the accounting platform, an electronic signature is applied automatically, and the signed file is dispatched to the correct supplier contact on a schedule we define, without anyone opening the document first.

Beyond the sending itself, we need visibility into what happens after a document leaves our side. The workflow should record when a supplier opens the file, whether their side has countersigned it, and flag anything that stalls so our finance team can follow up instead of discovering a missed payment weeks later. Retry logic for failed deliveries and a simple log of every dispatch would also help us stay audit-ready.

We are open to different technical approaches as long as the result is reliable and doesn't require daily manual intervention. Please describe your experience with similar accounts-payable automation before we discuss the technical details.

What we expect from the solution:
— automatic invoice generation pulled straight from accounting records
— electronic signature applied without manual steps
— scheduled dispatch to suppliers with status tracking
— alerts for signing delays or delivery failures
— an audit trail covering every document sent