I'll suggest USPS.com USPS is an independent agency of the U.S. federal government. They have around 13M visits per day [1]. Their website looks modern althoug

I'll suggest USPS.com USPS is an independent agency of the U.S. federal government. They have around 13M visits per day [1]. Their website looks modern although I'm uncertain about their uptime. [1] https://analytics.usa.gov/postal-service https://analytics.usa.gov/postal-service