He delivers the mail, but a Texas postman is setting records for another kind of delivery he makes. It's a delivery that is saving lives.

Every two weeks for the past 34 years, Marcos Perez spends two hours donating blood at the South Texas Blood & Tissue Center.

Perez donates platelets, a blood component that allows him to donate more often than if he were donating whole blood or double red blood cells (also known as power red), which people can also donate at STBTC.

"They might live an extra day, a year, a month, who knows. Maybe they will live forever," Perez said. "Somebody needs these platelets, and there's no platelets on the shelf."

Perez is the fourth person in South Texas to pass the 100-gallon mark, saving thousands of lives in the process.

"Don't cost me a dime, only some time," he said. "I'm 57 and I've already got 100 gallons! These other people are in their 70's or 80's!"

This milestone happens at a crucial time for the South Texas Blood & Tissue Center. During the summer, they tend to see a decline in blood donations.

"Mr. Perez is what you'd consider an All Star for the blood community here in South Texas," said Roger Ruiz, a corporate communications specialist for the South Texas Blood & Tissue Center (STBTC). "Mr. Perez has probably saved patients going through cancer treatments, patients who have been in car accidents, patients who have blood disorders."

Why does he do it?

Perez was born a premature baby, and needed a blood transfusion. He's now returning a favor tenfold.

"When I was growing up, my dad told me a friend of his donated blood for me," Perez recalled. "His name was Mr. Aguilar. He took the time to donate, so he saved my life."

Perez still keeps in touch with his lifesaver. He says that since his father passed away a year ago, Mr. Aguilar stepped in to fill the void.

On Wednesday, family members and employees at STBTC celebrated the big milestone. Perez is the second San Antonio mailman to accomplish donating 100 gallons of blood.

Whether its mail or platelets, this postman plans to keep delivering.

"If you make time to go eat, you make time to go to the movies, you can make time to come donate," Perez said. "Just make some time. Give from the heart. That's what it takes. You gotta give from the heart."

Perez joins the ranks with Ron White, who donated his 115th gallon of blood last week.

STBTC says:

Ron started donating after seeing his uncle donate blood when he was a kid. Since then, he has wanted to help others just like his uncle. As a 115 gallon donor Ron has saved the lives of over 2,700 patients. Ron says that is a great but is happy knowing that he saved the life of at least one person. Ron celebrated the achievement with STBTC staff and his family and says he looks forward to celebrating again when he receives his 120 gallon recognition.

Ruiz says that they are especially in need of O positive and O negative donations. Each donation, he says, can save three lives.

"O negative is the universal blood type and can be transfused to anybody who is in a trauma accident or who needs blood right away," he said. "Platelets, plasma, red blood cells, we need it all."