Question : Multiple MX IPs, SMTP connectors on one Exchange server

My company wants to set up another SMTP server to handle Emails for it's weekly "Email blasts".  From what I understand these are going out to companies that have asked for the information.  They want to do this to avoid having the actual business mail server IP blacklisted.  I understand Exchange 2003 has virtual SMTP servers and you can add multiple SMTP connectors but I can't seem to find good information on if I can do this.  Currently we have a Symantec Gateway the the SMTP connector is configured to send Email out through.  

What I have started to do so far is:
1 Add another IP to the NIC
2 Add another SMTP virtual server that uses that IP
3. Add another SMTP connector that uses that virtual server
4. Add the namespace for the Email Blast domain
5. Add the MX record for that domain on external DNS

With this the Email header shows that is goes out the Gateway IP which will not work.  I have also changed the address space on teh default connector to just have our regular domaini name spaces.

Is this even possible to do or am I just misunderstanding these concepts?  I understand you can setup relays through IIS but don't people get blacklisted for relaying Emails?

Answer : Multiple MX IPs, SMTP connectors on one Exchange server

Forget about getting Exchange to do this.
While you can setup additional MX records, SMTP virtual servers etc, what you cannot do is force the email to leave the Exchange server by any specific SMTP server. Exchange routes email based on destination, not sender.

You will need a separate machine, IP address etc, and possibly a separate domain or subdomain. Then configure that separate machine with the correct DNS, reverse DNS etc. Do not send the email through Exchange, it will not be able to cope.

Simon.