Microsoft holds that it does not scan the text or subject lines of emails. 'We work hard to make sure that ads are safe, unobtrusive and relevant.'

Google responded last week: 'Advertising keeps Google and many of the websites and services Google offers free of charge,' Samantha Smith, a Google spokesperson, told ABC News. ' is different - we don't go through your email to sell ads.'

And there's no way to opt out of this invasion of your privacy,' Microsoft's site says. 'Google goes through every Gmail that's sent or received, looking for keywords so they can target Gmail with paid ads. 'We don't go through your emails to sell ads,' a narrator says in Microsoft's latest 'Scroogled' advertisement. Microsoft began running its 'Scroogled' campaign last year, and has recently been running video ads on the web attacking Gmail and Google's ad targeting, which shows you ads based on words in your messages. Microsoft also took a swing at Google's advertising policies - which are at the heart of the new $30 million advertising and marketing campaign. Microsoft said at Outlook's launch that those features would differentiate it from its competitors, including Google's Gmail, which is the most popular webmail service with over 425 million users. The Sweep feature moves newsletters, promotional messages and other recurring emails into their own folders or to the trash. It also includes new social features and a sorting option called Sweep. was designed with a similar aesthetic to Microsoft's Windows 8 operating system. RELATED: Microsoft's 'Scroogled' Campaign Attacks Google's Gmail Ad Policies Microsoft expects the upgrades for Hotmail users to be complete by this summer. Hotmail users will still keep their email addresses and their contacts and emails will all be moved over, they will just now get a new user interface and all the new features of. Microsoft's Hotmail, which was originally MSN Hotmail, has been online since 1997. The service, which was announced last July, now has 60 million users and will now replace, Microsoft's older webmail system. Microsoft announced today that its new webmail service,, is coming out of beta testing and is now ready for primetime. We'll always remember you and all your 1990s glory.

Hotmail vs outlook