The latest round brings total funding to about $95 million and was led by private equity firm, Insight Venture Partners, with existing investor Dawn Capital also participating. This new cash brings total funding to a robust $95 million for the London-based company.

CEO Peter Bauer clearly sees opportunity beyond email archiving and collaboration to run on the company’s infrastructure ”Our top priority is R&D — we started building our platform in 2003 and now are ramping up the number of applications  to run on it,” he told me this week. Bauer thinks there are lots of interesting things that use all that unstructured data from email.

Mimecast plans to expand sales and marketing  – including building out the company’s channel partner roster especially in North America. Bauer also plans to double the company’s North America staff from the current headcount of 80, he said. US operations are based in Waltham, MA.

The company claims 6,000 customers including the Boston Celtics and has a particularly strong presence in law firms where proper email archiving is critical.

A few months ago, Bauer spoke to me about email fatigue — a problem Mimecast intends to address — and what it means for businesses.

“You hear about companies like Volkswagen switching off email after hours [to keep employees from burning out.] Many say there’s information overload problem with email and end users have expectations based on things like Facebook and LinkedIn,” he said.

“A lot of what they’re saying is right but the response is wrong … In reality email has to adapt  to meet new needs and be more collaborative in a way inspired by social networking. Email is the anchor tenant in how collaboration evolves. Email has such substantial adoption, penetration, network effects — the kids who have sidestepped email haven’t had a job.”

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

• A near-term outlook for big data
• Quality of the cloud: best practices for ISVs
• NewNet Q2: Google closes the quarter with a bang

What are the headline takeaways from the research? The first study, from email security and archiving firm Mimecast, found that just one in four work emails is essential and just one in three holds immediate value. The second study combed through the inboxes of disgraced Enron and revealed what emails do contain if not critical business information. The answer? Gossip. Of the 112 emails the average corporate email user sends every day a substantial 15 percent contain gossip, the research concludes.

The Mimecast results were drawn from 500 interviews with IT professionals, 200 in the U.S., 200 in the U.K. and 100 from South Africa. What other details of the corporate email inbox did the study’s less than flattering portrait reveal?

• Nearly two out of every three (61 percent) emails received are considered to be non-essential
• On average, 11 percent of email is personal, non-work related
• Seven percent of emails in the average inbox were spam
• 63 percent of email is internal, employee-to-employee communication

For the second study, assistant professor Eric Gilbert of the School of Interactive Computing at Georgia Tech examined hundreds of thousands of emails from Enron, hunting for gossipy missives. “Gossip” in this case being defined as emails that talked about a third party that was neither among the recipients nor the sender of the email. Exactly 14.7 of emails were revealed to contain gossip, with all levels of the corporate hierarchy engaging in gossip, though lower levels were more prone to swapping juicy morsels.

Could this level of behind-the-back chatter just reflect Enron’s ailing corporate culture? Gilbert thinks not. “Enron certainly had what could be called a ‘cowboy culture,’’’ he said, “but I suspect the way they behaved internally to each other did not differ significantly from most other U.S. corporations.”

And Enron’s email gossip wasn’t overwhelmingly things like complimentary comments about the new hairstyle sported by the colleague in the next cube over. Negative gossip was 2.7 times more common that positive gossip.  But despair not. Gilbert says gossip has its upsides.

“Gossip gets a bad rap. When you say ‘gossip,’ most people immediately have a negative interpretation, but it’s actually a very important form of communication. Even tiny bits of information, like ‘Eric said he’d be late for this meeting,’ add up; after just a few of those messages, you start to get an impression that Eric is a late person. Gossip is generally how we know what we know about each other, and for this study we viewed it simply as a means to share social information,” he says.

Why do knowledge workers continue to rely so heavily on email even though there’s mounting evidence that it’s a form of communication with big downsides?

Image courtesy of Flickr user Lars Plougmann. 

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

• How social discovery is transforming entertainment
• Personal tools lead to practical business
• Flash analysis: the future of Yahoo