When “Serial” launched its first season last year, the podcast true crime story from “This American Life” was a stunning breakout hit. Along for the surprise ride was Atlanta-based MailChimp, an email marketing company that was the podcast’s only sponsor at the start.

Now, MailChimp is back for season two, which just launched and focuses on Bowe Bergdahl, the U.S. Army soldier who left his base in Afghanistan  and was later taken by the Taliban.

But MailChimp is being closed lipped about its involvement with “Serial” this time around, at least for now. A company spokeswoman declined to comment this week.

That might be because the latest season reopens a controversial subject with more national attention.

It includes the first media interview with Bergdahl since his release last year in a prisoner swap. His words already are getting lots of news coverage.

Before the first season of “Serial” last year, the podcast’s co-producers hoped it would get 300,000 iTunes downloads. Instead, it landed more than 100 million.

MailChimp had a 19-second spot at the start of each episode in the first season. The company’s unusual name, which one person in the ad mispronounced as something like MailKimp, led to lots of parodies and social media mentions. All of which ought to have been good for business.

With a smiling monkey as its logo, the company says it has more than 10 million customers and sends over 600 million emails a day.

Related on the podcast front: Listen to The Atlanta Journal-Constitution's true-crime podcast series "Breakdown."