How long does it take to mail a letter from Michigan the London?

It depends on the type of mail service chosen and any potential customs procedures. However, generally, it can take anywhere from 6-10 business days for a standard airmail letter to arrive from Michigan to London.

For faster delivery, express or priority mail services can be used, which can take approximately 2-3 business days. Please note these times are approximate and can be affected by factors such as international border regulations, delays, and any additional processing required by customs or postal services.