Google's solution is much cheaper

"Apparently the NSW Department for Education is deciding to do away with MS Outlook and instead adopt the Gmail account for its 1.3 million school students. SMS Management and Technology will implement the new Gmail System along with Google and Telstra, under a 3-year deal worth $9.5 million over three years, with a two year extension option. In comparison, the earlier MicroSoft deal was installed by Unisys under a contract worth $33 million over 3 years, but extended by another 3 years. It was built in 2003, but actually reached the student during 2007."

[source]

As we can examine Google solution much cheaper and I guess more flexible. On my current work, I have similar problem. My email box is 40Mb in size. It's inconvenient I always clean my email box.

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