Outlook 2003 ignores [E]SMTP welcome banner and refused to send mail. (Receiving works fine through

Hi Folks,

I'm running Outlook 2003 (SP3). Outlook is not recognizing the SMTP
greeting from the mail server and as a result terminates the connection
without doing anything. I have tried all combinations of:
PORT: 25, 587
AUTHENTICATION: Required, Optional (Plain Text, NTLM, GSSAPI)
ENCRYPTION: Required, Optional (TLS - Self-signed Certificates)

None work. I would expect I should be able to at LEAST get port 25, no
authentication, no encryption to work, but no...

Outlook 2003 ignores [E]SMTP welcome banner and refused to send mail. (Receiving works fine through