From the gmail site...
You can use the following information to configure POP with many mail clients.
Incoming Mail (POP3) Server - requires SSL:pop.gmail.com
Use SSL: Yes
Port: 995
Outgoing Mail (SMTP) Server - requires TLS:smtp.gmail.com (use authentication)
Use Authentication: Yes
Use STARTTLS: Yes (some clients call this SSL)
Port: 465 or 587
Account Name: your Gmail username (including @gmail.com)
Email Address: your full Gmail email address (username@gmail.com)
Password: your Gmail password
Normally when I see this problem, it is due to wrong port settings