Certīs for Exchange ActiveSync are a 2 part issue.
1) the server
2) the client
The client is usually shipped with some preinstalled certificates from the
largest/most popular authorities so if your server uses that authorities
cert then you are fine.
You can on the SERVER disable requiring certs and then in Smartphone 2003
you can select to not use certs and go cert-less but you need to do this at
both ends.
The disable cert tool is just to allow you to connect with a server
generated (as opposed to authority generated) certificate.
Here are some articles that might be helpful.
Add Root Certificates to Pocket PC 2002
