Do you have both POP and SMTP set up? Normally you'll only need SMTP if they have an on-site mail server. I wonder if having both may cause a conflict.

1) [1101] Baud Rate – Default 38400
2) [1104] Ethernet Settings: Enter IP, Subnet, Gateway and at least one DNS
3) [1105] Enable SMTP
4) Enter the Server Name or IP address that handles the SMTP
5) Enter User Name and Password only if the SMTP server requires authentication for every log-on.
6) Enter SMTP account email and Reply to email
7) Port 25 needs to be open on the network

"I'm the one that has to die when it's time for me to die, so let me live my life, the way I want to."
-- Jimi Hendrix