Suggestion: When you mail PO, its does not have any file name, it has just .pdf as document. Will it possible to give meaningful name to file? It will enable PO recipient to track better.
Please don’t divert topics with unrelated questions. Your suggestion has nothing to do with sales quotes.
if you have set a subject for your purchase order in the email templates under settings, this subject will automatically show as the pdf file name when you mail it.