We've rounded up 4 unique methods for writing proposal submission emails. Plus, we've got email samples for each method.We have reviewed ten of the best proposal templates we could find online across various industries. These proposals showcase multiple proposal formats. This proposal email template is designed for impressing clients with your achievements, social proof, or positive testimonials. 1. Read the Contract or Terms of Agreement. Be sure you agree with the requirements and restrictions. First, you'll want to reach out to your client and gather all necessary information about their business and goals. 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.