MsExchangeTeam explained three methods to stop unapproved devices from accessing Exchange data.
Many companies and users consider mobile access to Exchange data an essential feature. Exchange ActiveSync (EAS) is very popular as it allows this access and many devices have licensed and implemented EAS (including Windows Mobile). Some companies use remote servers to access Exchange data and push it out to their mobile clients that aren't EAS enabled. Of course these mobile access options can be a little concerning when you think about the security implications. Evaluating these devices (and servers) to make sure they comply with data protection policies is a necessary step for a lot of companies that want to protect their messaging data. This post will details some of the options available to companies that want to limit access to a specific set of supported devices.
The first question we usually get is, "How do you stop unapproved devices and servers from accessing Exchange data?" In general, I hear people talk about three ways to block devices:
- Use an ISAPI filter (Not recommended)
- Set policies that only the devices you care about can implement (Better)
- Block the devices at the firewall (Recommended!)
Read more at source: http://msexchangeteam.com/archive/2008/09/05/449757.aspx