Earlier this week, we asked if Microsoft was getting its mojo back, citing the positive reactions to the company's Bing Maps and Windows Phone technologies. But, as we all know, Microsoft makes most of its money off products like Office and Exchange. Now, through a series of YouTube videos, Microsoft is fighting back against its chief rival in those core areas too arguing that its products provide "more total value than Google Apps."

In the video comparing Microsoft Exchange to Google's Gmail, the company points out security, administration and integration issues when Gmail is used in the corporate environment. "We have shown you just a few examples of how Google struggles to deliver the basics of business critical email," the narrator of the video says at one point.

This is shaping up to be an interesting battle. That's because Google and Microsoft are starting to actively defend their home turf, while at the same time expanding into each other's core markets. (Some have argued that Google's recent Super Bowl ad was a response to the rising share of Microsoft's Bing search engine).

In addition to the videos, Microsoft also is touting a Web site -- www.whymicrosoft.com -- where potential customers can compare Microsoft technologies to offerings from Cisco, IBM, Google and others.

However, there's one place where Microsoft appears to have ceded ground to Google. TechCrunch points out the irony that the new videos are being hosted on YouTube, which is owned by Google.