Return Path, a company that helps marketers and publishers make sure their e-mails don’t end up in your spam folder, has acquired competitor Habeas for an undisclosed amount.

Return Path chief executive Matt Blumberg says Habeas announced that it was looking for an acquirer earlier this year, and the deal made financial and strategic sense for his company. The combined organization now spans both coasts, since New York-based Return Path will keep Habea’s Mountain View, Calif. office’s open.

With the acquisition, Return Path now has around 1,500 customers. Both companies manage “whitelists” of approved email contacts — Return Path has SenderScore, while Habeas has its SafeList. The current plans is to keep the lists separate.