What to punctuate: holly medical center 55 e panlin circle atlanta georgia 30320 dear dr remo

Assuming this is a letter head, you'll want to format it like so:

Holly Medical Center
55 E Panlin Circle
Atlanta, GA 30320

Dear Dr. Remo,

you place a comma between a city and a state (Atlanta, GA) and you leave the zip code with the city and state. with the address (Dear Dr. Remo), you must place a comma after it to show that it isn't a full sentence and you plan to continue with your letter.

Commas in between every section and a period at the end