[niteriderxp]

As others have stated, Exchange 2007 works with Activesync without additional licenses or software. However, there is some configuration required.

The server must have port 443 (HTTPS) open to the outside on the firewall, some companies also open port 80 (HTTP). We only have HTTPS open on our firewall as we want to ensure that SSL encryption is always used. We require TLS transport between us and some business partners, so it does us no good if email access is unencrypted.

Your Exchange server should have a "Unified Communications" SSL Certificate. The certificate should have your publicly accessible domain name e.g. yourdomain.com in the Subject and any additional names required by the server in the Subject Alternative Name (SAN) e.g. yourservername (netbios name), yourservername.yourdomain.com (FQDN), autodiscover.yourdomain.com (autodiscover url). These domains then have to be configured into Exchange.

The certificate can be issued by your domain's Certification Authority (CA) or a public CA. If it is issued by a Public CA it does not have to be installed on each computer or phone client. If it is self-signed, then the CA's certificate has to be installed on each client.

When everything has been setup, Exchange Activesync has to be enabled on the server and on the individual account using Exchange Management Console.

Then configure Activesync on your phone using the certificate's subject name.