We've rounded up 4 unique methods for writing proposal submission emails. Plus, we've got email samples for each method.A business proposal email is a persuasive sales document sent to clients to gain business. Learning how to write an effective business proposal is essential. This proposal email template is designed for impressing clients with your achievements, social proof, or positive testimonials. We'll show you an example of a followup email to send a client after sending a proposal so you actually get a response! The City of Sacramento is seeking proposals for vending products and services from vending machine operators. Drew Golbin, RFP Coordinator. Learn how to craft an effective business proposal email with our comprehensive guide. Please provide one example of how your firm committed capital on behalf of municipal clients in the past year. 4.