The Breast Cancer Research Stamp is actually sold all year round, at a higher cost of 55 cents.
The extra amount of postage is divided between the National Institutes of Health and the Medical Research Program of the Department of Defense.
Sales of the stamp have raised almost $71 million since 1998.
"We're just excited here in the Mississippi district," said Pamela Lowery of the Meridian USPS. "Thus far, this month we're the number two district in sales. And we've raised just a tremendous amount of money that will go toward, I think, it's almost $45,000 that will go toward finding a cure."
Lowery says postal employees also take advantage of the opportunity to encourage people get regular mammograms and do self-exams, so that the cancer is caught as early as possible.