Exchange's push wireless e-mail will keep attracting users to Microsoft, Radicati predicts Microsoft will stay at the top of the growing corporate e-mail market, thanks partly to its software’s new wireless push capabilities, according to a new report from The Radicati Group.The study found that Exchange, Microsoft’s e-mail platform, currently has 23 million more seats than Lotus Domino, IBM’s e-mail platform. The addition to Exchange of push wireless e-mail, which is part of the Service Pack 2 upgrade, should keep driving users to Microsoft in the future, Radicati predicted.Spam will continue to be a problem regardless of which platform enterprises use. In 2005, spam traffic totaled 91 billion messages per day, the report found. By 2009, spam is expected to reach 228 billion messages per day, Radicati said. Messaging software, including e-mail software used by enterprises and software used for hosted e-mail services, will generate $3.6 billion in 2009, up from $2.5 billion in 2005, the report said. Software DevelopmentSmall and Medium Business