I am setting up a Nokia Lumia phone, which runs Windows Phone 7.5 “Mango”. I am impressed with the smoothness of the setup experience, though I had one slight hassle which I do not blame on Nokia or Microsoft because it is is not typical.
I run an Exchange Server (and SharePoint) for test purposes with a self-signed certificate. On the iPhone and I think Android, you just get a warning the first time you connect and after that it all works. Windows Phone though gives you a certificate error when Outlook tries to connect and will not let you proceed further.
Which of these approaches is right is a moot point: convenience versus security I guess.
Fortunately it is not too hard to get Windows Phone to trust your certificates. Here is what I did:
1. Email the certificate(s) to myself on Google Mail.
2. Go to Google Mail in the phone’s browser. For this to work I found I had to use the Basic HTML view, as the mobile view did not let me download the attachments.
3. Open the email you sent to yourself. Tap the attachment. Windows Phone offers to install the certificate, tap to install.
4. Now go back to Outlook and synchronise, everything works.
You will also need this for SharePoint if you want to use Office on the device.
Of course if your Exchange and SharePoint use a certificate from a trusted certificate provider then these steps are not necessary.