(Maxwell Cooter, CIO) The battle for email cloud is set to heat up as enterprises start to rethink their email strategies, that's according to Forrester chief analyst, Ted Schadler.

In a new Forrester report, Four Giants Compete For Your Cloud Email Business, Schadler explains how the advent of cloud services is going to shake up enterprises' spending on email.

Email is going to the first large-scale cloud application wrote Schadler. "The reasons are simple: Email in the cloud is cheaper; it will evolve faster; and it is a commodity application that an email provider can run." Not only that, it's a great test bed to master the issues of cloud computing providers. And we're not talking about being a little cheaper either. Cloud-based email is going to be a lot cheaper "unless you're a 50,000-person company with a highly centralised email platform or you run hardware and software until it's old and crusty and a decade behind the times." Schadler wrote.

But when it comes to deciding which company is going to dominate the market, the issue is not so clear cut. With four major companies offering similarly priced services, the differentiators are going to be the level of integration that they offer.