If you are able to receive email but can't send through Outlook Express, please check the following:
1. Select Tools
2. Click on Accounts
3. Click on "Properties" button
4. Click on "Servers" tab
5. Check on "My server requires authentication" (There should be a check mark on this option)
6. Click Apply
7. Click OK
8. Check if you could send email after the above changes
If the problem persists, please post a support ticket along with the following information:
a. email address
b. email address password
Note: If the above solution does not work, the problem may be on your ISP. Contact your ISP and check with them if the SMTP port has been blocked. Some ISP block SMTP port due to spamming in their network. In this case, we recommend using your ISP's SMTP setting for trouble free sending.