In the marketing world there are emails and then there are Sailthru emails.

Sailthru specializes in a unique kind of personalized email marketing that helps media companies and marketers tweak emails based on what they know about individual readers. That’s music to ears of companies like Thrillist, SpinMedia and Khan Academy, all of which Sailthru counts as customers.

Now, in its third funding round, Sailthru is raising $20 million to push its vision forward to even more people. The company says it plans to use the new cash to expand its operations globally.

The latest round, which was led by Scale Venture Partners, joins the $19 million New York City-based Sailthru railed in February. The company’s raised $48 million to date.