Can I use Plusnet Spam Filtering with hosted Exchange

[#1]

Hi,
I host my own Exchange server. I have a domain name registered and DNS pointing to my Plusnet static IP. I have registered my domain name with an external registration company and use them for DNS resolution too. Is it possible somehow to use Plusnet as a mail relay for spam filtering purposes, or would I have to use Plusnet to host my domain name in order to do this?
Thanks,
Ben

[#2]

Hi Ben,
Yes, you can keep the domain with the current hosts and have us make an entry on our DNS so you can relay via us. As long as your server is connected to a Plusnet service that should work just fine. Let me know if you need advice on how to go about this.

[#3]

Adam I can't see this working. If he's running his own exchange server he's probably using SMTP for his mail delivery, in which case the MX records will be pointing directly at his IP address. I'm not aware of a way to configure inbound emails to go through the Ironports and then be delivered to a users SMTP server!

[#4]

For inbound mail, Bob has stated that this isn't supported.
B.