Unable to send email with MS Outlook 2003 with Win XP Pro

One of my users is on a PC with Win XP SP3 and MS Outlook 2003 (as the email editor)

I can receive email without any problems, but cannot send.

I’m not getting any error being reported and the application just does nothing. I have done the following using regedit: Regsvr32.exe %Windir%\System32\Ole32.dll

I am not sure what it wrong.

My users are using a POP3 server for sending and receiving email