The U.S. Postal Service said Thursday that it has reached a multi-year, $10 billion deal to deliver packages to customers’ doorsteps on behalf of DHL eCommerce, the online-retail arm of German logistics provider DHL. The agreement cements the postal service’s strategy of opening its last-mile delivery network to shippers large and small — a move first signaled in December when the agency said it would expand beyond its existing last-mile contracts with Amazon and UPS.

Last-mile delivery refers to the final leg of a package’s journey, from a regional distribution hub to a residential or business address. It is the most labor-intensive and costly stage of the shipping process, and control over it has become a key competitive differentiator for carriers, retailers, and logistics firms.

“Because we deliver to 170 million locations six days a week, we are the best last-mile provider by default,” Postmaster General David Steiner told reporters on a call Thursday. “For us, this is a matter of meeting the customers where they are and meeting the customers’ needs.”

Neither the USPS nor DHL provided details on the agreement’s duration or financial structure beyond the $10 billion headline figure, describing it only as a long-term commitment. The deal comes as the postal service seeks to stabilize its finances by growing its package business, which has become an increasingly important revenue driver amid a long-term decline in first-class mail.