Users of email management software from Bronto Software skyrocketed in the second quarter to more than 200 customers, the company says.

Fifty-five customers signed on, including such high-profile clients as Lending Tree and Kaplan Professional Schools. Several international clients also became users.

“We had a strong second quarter as demand for our web-based email management software continues to grow,” said Joe Colopy, president of the two-year-old firm. “Clients have found Bronto’s web-based software to be a great tool for managing email contacts and sending out email newsletters and surveys.”

Bronto also moved into bigger office space in July at the American Tobacco Historic District of Durham.