Broadwick, a developer of permission-based email marketing software, has climbed past the 2,500 customer level, the company said Tuesday.

Broadwick customers have also now sent more than 250 million messages using its IntelliContact Pro product. The program is designed to avoid spam.

Of the email messages sent, some 15.6 percent were opened and the click-through rate from recipients was 2.4 percent, Broadwick reported.

Among its customers are Fortune 500 companies International Paper and Super 8 Motel plus Re/Max and the Lance Armstrong Foundation.