How To Write A Letter To London From Usa . The date is written as “15th may 2008” not “may 15, 2008”. When sending a letter internationally, you will first need to go to your local post office and pick a mailing service. Letters « The Spirit Of America Tour from spiritofamericatour.org Postage for letters mostly depends on weight and size/shape. Print addresses neatly in capital letters. To make sure your enquiry finds its way to the right inbox, please complete the form below.