Thoma Bravo, a software-focused private equity investment firm, has acquired a majority stake in Mailgun Technologies, a provider of email infrastructure software, from Turn/River Capital. The investment recognizes Mailgun’s strong momentum and includes growth capital to help the rapidly growing company expand its platform and accelerate product roadmap initiatives. As part of the transaction, Turn/River and the company’s management team will retain a minority ownership stake in the company.

Mailgun provides email API technology to over 150,000 companies, enabling developers to send, receive, and track email easily from within their applications. Software development teams at Lyft, GitHub, Iterable and Indeed seamlessly embed Mailgun within their applications to power high-volume and high-frequency email messaging. Mailgun’s robust infrastructure technology, combined with best-in-class developer documentation, developer tools and customer support, ensures market-leading deliverability across several types of emails, including transactional and marketing use cases.

“Mailgun’s partnership with Thoma Bravo gives us the capital and operational expertise needed to continue growing our company, expanding our product suite, and building upon a truly comprehensive developer-focused offering,” said Will Conway, CEO of Mailgun. “Thoma Bravo has a proven track record of helping software companies achieve exceptional results, and we look forward to leveraging their investment experience.”

Thoma Bravo has provided equity and strategic support to experienced management teams of growing companies for nearly forty years. The firm’s investment in Mailgun is the latest investment in infrastructure software. Previous infrastructure software investments for Thoma Bravo include Dynatrace, Embarcadero, Flexera, Kofax, and Solarwinds.

“Thoma Bravo believes there is tremendous growth potential in the email infrastructure market,” said Hudson Smith, a partner at Thoma Bravo. “Will, Josh and the entire Mailgun team have built the leading product in the space with their developer-centric approach, and we are looking forward to a strong and productive partnership with them.”

Mailgun was advised by William Blair & Company and Choate, Hall & Stewart. Thoma Bravo was advised by Harris Williams and Goodwin Procter.