View as a Web page and/or PDF for any email

We are using Sendgrid with dynamic templates and often are asked for a "printable" Web version of receipts and invoices or PDF copy.

Unfortunately, Sendgrid offers none of the following, so we built a side-car that allows simply adding a link to a template (no integration or engineering work), and clicking on it would generate either a Web version of email or a PDF copy of it.