Simply replace the unfilled areas such as "" and "[date]" with your information.
Dear [contact at client business],
Thank you for the opportunity to serve you. We are very excited to work with you regarding this project, and feel that this business relationship will be beneficial to all parties involved.
As previously discussed, we are enclosing the contract for this project. We have included all terms agreed upon. We ask that you review this contract, make any necessary changes in the margins and forward it back to us. If no changes are required, we ask that you obtain all the proper signatures on the contract and return it to us with the requested payment.
Once we receive the executed contract and payment, we will immediately begin work on your project.
Again, thank you so much for the opportunity to work with you.