"VMware is well positioned to understand the needs and desires of the Zimbra product and its customer base. I feel we will see some convergence between the two business divisions bringing interoperability between Zimbra and VMware products," Day said.

L. Mark Stone, CIO at managed services provider , a Zimbra customer as well as hosting partner, views the acquisition as potentially positive, but warns it could sour if VMware becomes impatient for revenue and makes decisions focused on short-term results, as it seeks to diversify beyond virtualization.

"If VMware builds on Zimbra's brand and supports their entrepreneurial culture, the acquisition will be good for Zimbra partners, customers and other stakeholders," Stone said via e-mail.

"Zimbra is a great SaaS offering, but if VMware tries to over-monetize Zimbra too quickly, that will be a problem," he added.

Stone warns that VMware must be aware that Zimbra's competition has improved greatly, including Exchange, whose 2010 version he calls a significant enhancement over Exchange 2003.