How To Write A Moving Letter To Clients . Simply write “dear” and follow it with the name of your specific audience or just use a generic name such as “whom it may concern.”. Specify the case and its status. Farewell Letter To Colleagues Farewell letter to colleagues, Farewell from www.pinterest.com This is an opportunity to deliver a branded message about how the change in location will make their experience with your company better. While your case closing letter should be tailored to your firm and your client, consider including the elements below. Give the clients time to receive the letters by mail and then send an email.