While parent company Yahoo mulls an unsolicited acquisition bid from Microsoft, Zimbra on Tuesday shipped a version of its e-mail and collaboration software suite that adds support for BlackBerry devices and Outlook 2007.

Version 5.0 of the Zimbra Collaboration Suite (ZCS) lets users synchronize e-mail, contacts, calendars and to-do lists with Outlook 2007.

Meanwhile, it also extends its mobile reach via support for the BlackBerry Enterprise Server, allowing users to access Zimbra on all BlackBerry devices. Also on the mobile front, ZCS 5.0 also lets users tap into Zimbra from J2ME devices and from any mobile Web browser, including the iPhone's.

"Mobility is a huge strategic priority and an area where we'll invest a lot in," Satish Dharmaraj, Yahoo vice president and Zimbra co-founder, said in an interview before Microsoft's US$44.6 billion unsolicited bid for Yahoo was announced on Friday.

There has been a heavy interest among Zimbra's enterprise and education customers for BlackBerry support, while consumer clients pushed for J2ME and mobile Web access, he said, adding that Zimbra plans to build a native application for the iPhone.

In addition, the suite's Web client now has a to-do application for tasks management, an instant messaging application that allows group chats, and the ability to work while offline using Zimbra Desktop.

The expanded mobile access and the offline support are important enhancements that will resonate in the enterprise market, where the Yahoo association doesn't help Zimbra, said Rebecca Wettemann, an analyst with Nucleus Research. "Those are key pieces for them," she said.

With ZCS 5.0, Zimbra is also making available optional "zimlets" or widgets that link the suite with Yahoo services like Flickr, Yahoo Local, Yahoo Finance and Yahoo Search. Meanwhile, Zimbra technology is being brought to Yahoo Mail and Calendar, due later this year.

Zimbra currently provides 11 million paid mailboxes to customers in more than 70 countries. Customers include Red Hat, Texas A&M University, European ISP (Internet service provider) Eircom and Brandeis University.

ZCS 5.0 is free in its Open Source Edition, while fees vary for the Network Edition commercial version, which customers can try out for free for 60 days. ZCS can be downloaded and installed by customers on premise or used as Web hosted software-as-a-service.

In addition to its core e-mail application, the suite also has a word processor and a spreadsheet application that let users create, share and collaboratively edit documents. It also has a calendar and contacts list.

ZCS competes against Microsoft Office and Exchange in the on-premise software market, and against Google Apps, Zoho and Cisco's WebEx in the software-as-a-service market.

Yahoo surprised many when it bought Zimbra in last year's fourth quarter for US$350 million. At the time, Zimbra customers in general expressed concern about the future of the suite if Zimbra became part of Yahoo, whose focus in on the consumer Internet market.

Now, with Microsoft intent on buying Yahoo and Google reportedly seeking to derail the deal with a Yahoo partnership, Zimbra is in the middle of potential corporate turmoil and uncertainty.

Whatever happens, Zimbra's suite should be seen by either Microsoft or Google as complementary to their collaboration and communication products, Wettemann said.

For example, Microsoft could leverage Zimbra's software to accelerate the addition of Web 2.0 and software-as-a-service features to Exchange, Office and Sharepoint, she said. Meanwhile, Google could possibly use Zimbra software to provide a solid offline component to Google Apps, Wettemann said.