We do not support Outlook 2003, but are leaving this article here in case it may be of some use.
- Open Outlook
- Click on Tools
- Click on Email Account
- Select View or Change Existing Email Account
- Click Next
- Select your Email Account
- Click Change
- Click on More Settings
- Click on Outgoing Server Tab
- Select My Outgoing Mail Server Requires Authentication
- Select Use Same Settings as My Incoming Mail Server
- Click Ok
- Click Finish