Yahoo has reached an agreement to sell its open source Zimbra e-mail collaboration unit to VMware. Financial terms of the deal were not disclosed, but VMware said it expects the deal to close in the first quarter of calendar 2010.

When Yahoo acquired Zimbra in September 2007, some Zimbra backers worried Yahoo would mismanage the open source email asset. Fast forward to the present, and some Zimbra proponents have gone from concern to outright panic over Microsoft’s bid to acquire Yahoo (and, by attachment, Zimbra).

We don't for certain that VMware, the giant proprietary virtualization company, is buying Zimbra, the open-source e-mail server company from Yahoo, but that's the news from the rumor-mill.

It’s been less than a month since VMware officially acquired Zimbra -- the open source email platform -- from Yahoo. But VMware isn’t standing still. Jim Morrisroe, VP and GM of VMware’s Zimbra division, says the company is preparing software appliances that combine virtualization with Zimbra. They should arrive by Q2 2010. Here are the details and the implications.

VMware is poised Tuesday to further redefine its cloud strategy by buying Yahoo's Zimbra open source messaging business in order to expand its stake in the platform-as-a-service market. Zimbra, bought by Yahoo in 2007 for $350 million, is an open source messaging platform popular on the Linux and Mac OS platforms and with universities and service providers.

VMware’s one year old, Zimbra saw its latest version, Zimbra.7 being unveiled on Monday last. VMware had acquired Zimbra from Yahoo January last year as it did not quite get the leverage the software required with Yahoo’s non-PR attitude.

Microsoft’s proposed $45 billion buy of Yahoo would give the Redmond, Wash company control over a top open source e-mail company, open source projects and an open source infrastructure. On September 17 of 2007, Yahoo bought Zimbra for $350 million. Yahoo’s infrastructure is built on BSD. Yahoo has released a myriad of software to the open source community and even sponsors some open source projects. So this deal would put Microsoft directly into the open source software business.

Zimbra, one of the best-known providers of open source email, may soon have a new owner. Rumors are swirling that Yahoo plans to sell Zimbra to VMware. If true, here are the implications for Zimbra business partners.

U.S. antitrust officials have approved Yahoo's (purchase of e-mail software maker Zimbra for $350 million, the Federal Trade Commission announced on Monday.
Antitrust authorities took a preliminary look at the deal and said it posed no antitrust concerns, the FTC said in a statement