Outlook 2003 sending problem

Hello,

I am running Outlook 2003 on Windows XP SP 2. I have been using this for over a year. Last night i sent out emails.
Today i flew away on a business trip, and i am hooked up to wirless in my hotel room. Now i can’t send out emails. i recieve error report
Task ‘mail.lettercredit.com – Sending’ reported error (0x800CCC13) : ‘Unable to connect to the network. Check your network connection or modem.’
When i go into the account settings and test them, everything works fine. I log on and send the test email. But when try to send a an actual mail, i get this error report. I can recieve emails just fine. Please help me! I need to send out email from my outlook.

Thank you,
Alex