If a business proposal sent to you meets your investment criteria, you could either accept it on the email directly or through your dashboard.
Visit the Messages section on the top right of your dashboard to view all proposals received. Click on the "View" button to see the business details as shown below. Type your message to the business and click on the "Accept Proposal For Free" button to connect with the business.
To accept a proposal from your email, simply click on the green "Connect" button as shown below.
Please note that accepting a proposal is free and your introduction credits are not used when you connect with a business or franchise which has sent you a proposal. For more details please refer to: Do my credits get used if I accept a proposal?