SendOwl

Usually reliable tool shopify, with even some interesting features like pdf stamping and drip function.
Been using this for years. Lately got somewhat disappointed with communication, like in a recent two day semi-outage, where nothing was proactively communicated, not before, not during, not after. Hence detracted one star.

Great so far! Worth the monthly fee as well! I appreciate the added features like link expiration limits, putting the customer's names on the PDF's for security, and that they DON'T automatically mark certain purchases as fulfilled when the digital downloads are sent in addition to physical products that are not yet fulfilled. My only issue is that by having the customer name automatically put on the PDFs, it takes away the interactive feature from the PDF.