The United States Postal Service at Adams Ave. and Harbor Blvd. in Costa Mesa is praised for its helpful and professional staff. Many customers appreciate the quick and efficient service, especially when dealing with issues like missing packages or passport tracking. Supervisors, including Quang and Joy, are noted for their excellent customer service and support. However, there have been ongoing concerns regarding the availability of specific items, such as Christmas stamps, which have been consistently out of stock for the past three years. Despite this issue, the overall sentiment towards the post office remains positive, with long-time customers expressing gratitude for the team's efforts and improvements in service. The commitment of the staff to assist customers in challenging situations stands out, making this post office a valued part of the community.