It’s been a big day for email today. Apparently Yahoo has agreed to purchase Zimbra, the open source messaging and collaboration company, for (US)$350 million. Opinion has been varied on whether it’s a smart move by Yahoo or a gross over-valuation of Zimbra.

Zimbra is a company that I’ve been monitoring since their public launch back in 2005. At the time they noted (as many have) that email is broken.

“From overflowing inboxes to the nuisance of organizing correspondence, to the cost of managing storage, viruses, availability, retention and legal discovery and compliance, dealing with corporate e-mail has become a nightmare.”

Zimbra have worked to address these problems with their Collaboration Suite software (ZCS), which is notable for the fact that much of the source code is released under an open-source licence.

Regardless of your take on Yahoo’s purchase, what’s interesting is that this deal clearly shows the value that the market places on an alternative to Exchange/Outlook, and Lotus Notes, even an open-source one. I read this as recognition that there’s plenty of room left for innovation in the email and collaboration space.