sales invoices and quotes have a .PDF extension versus a .pdf extension

Sage 50 Quantum 2016 using Sage 50 E-mail Writer v2 (powered by Amyuni Document Converter 450)

Sales invoices and quotes generate with a .PDF extension rather than a .pdf.  Everything else (reports) generate with a correct .pdf extension.

How do I configure so Slaes invoices and quotes get a .pdf