Sina (SINA) and Netease (NTES) jointly announced that they would expand the capacity of their respective free email boxes to 1.5 Gigabytes.

This is the first time that the two companies have initiated such a cooperative move.

What is perhaps more interesting is that the companies' announcement also pointed out some improper email behaviors of certain enterprises. For example, the companies said that some unnamed Internet companies in China provide false capacity expansions that allow too much spam through their systems.

Though they were not directly named, Sohu, MSN and Yahoo are the other three largest email providers in China. None of these companies have issued responses.