The MMEG "physical address" is simply another mailing address with an internal mail box number at that address.
A simple Map search shows a UPS Store with the same address as the shopping center. The #301 is the UPS Store location in the shopping center and the #252 relates to the mail box within the UPS Store location.
UPS Store is next to #302 at that same address which is "Lamar Jewelry/Nails". an easy Map search will display the pictures of that location.