Gmail uses non standard ports for POP3 and SMTP:
Incoming mail server (POP3): pop.gmail.com port 995
Outgoing mail server (SMTP): smtp.gmail.com port 465
Download The Gmail POP Troubleshooter tool at the url below to help make the setup simple
What is the Gmail POP Troubleshooter?
The Gmail POP Troubleshooter tool helps you with the setup of Outlook, Outlook Express, and Thunderbird 1.5 for POP access to your Gmail account.
By checking client settings, server ports, and connection to the Gmail service, the tool is able to pinpoint any errors and provide instructions on fixing them. The Troubleshooting tool also generates a report detailing your settings and test results -- if you have trouble, you'll have the option of sending your report to Google for further troubleshooting assistance.
Requirements: works with Outlook 2000, 2003, and 2007, Outlook Express 6, and Thunderbird 1.5. Currently only available for Windows.