There are three ways to get CCIM Gmail on a Treo 650:

 1. Use the web browser, go to http://mail.google.com/a/ccim.net/h/ 

Treo tip: Assign the url to a favorites button in the telephone view (a "G" will do fine if its not already assigned). This enables the user to press and hold the "G" button while in the telephone dialing view, which will take you directly to the Gmail mobile site.

Note: This method one worked only after I acknowledged that I was not an "administrator" the first time I accessed it, and fine thereafter. 

2. Use Versamail email program that comes with the VERIZON Treo 650: Use the account settings that the Gmail wizard sets up on Outlook Express. Pay close attention to the port assignments and SSL; they are not the default settings.

I had a problem sending email, so I googled the problem with the error messages. The following helped solve the problem:

http://www.everythingtreo.com/forum/applications/accessing-gmail-using-versamail-on-your-treo-2984-5.html

In short, configuring the SMTP server on port 465 or 587 (with SSL) didn't work for VERIZON, however, configuring the SMTP to use port 25 (with SSL) AND ESMTP worked fine. 

Note: Different cellular networks require different port assignments, especially for the outgoing email. This discourages email relaying (Washmymail allows relaying).

3. Use the new Gmail Palm application  http://mail.google.com/support/bin/answer.py?answer=52843&topic=10085 To get it, you have to use the Treo web browser, navigate to this site, tap the link, and download directly onto the cellphone. It knows what kind of cellphone is being used, and downloads the proper application. Note: The Gmail application requires a Palm/Treo provided java program to be installed from the original installation disk, or it will not show up as an application on the telephone.

I have not tried this one yet, but it promises to be the best way to access Gmail from a cellphone.

 Nov. 20, 2006: If you're accessing from your Treo and your PC, please read this article.