Problem sending e-mail via Verizon FiOS account

Wondering if anyone can help me with this issue. I have set up an e-mail account on my original iPhone (2G) and my new iPhone 3GS to access my Verizon e-mail account (I am a Verizon FiOS customer). Although I have no problem retrieving e-mail messages, I continue to receive an error when sending. I have deleted and set the e-mail account again, check the settings over and over but still can't send although receiving works like a charm.

As this a problem on two iPhone models, I thought I would throw this out and see if anyone else has experienced this and may have some recommendations for resolution.

Thanks,

Joe