Intuit will buy email marketing company Mailchimp for $12 billion in cash and stock, the companies announced Monday.

Intuit, which is known for financial service offerings like TurboTax and Credit Karma, said it will use the acquisition to accelerate growth among small business clients. It marks the company’s largest acquisition to date.

MailChimp was initially founded in Atlanta in 2001. Shares of Intuit were flat in after-hours trading following the announcement.