Currently I have a C350 configured with one interface which handles all inbound and outbound mail. I've been informed that there will be a marketing initiative where emails will be sent out from one of our web servers. I'd like to add the second interface and set up a rule to deliver those email from that interface as opposed to the primary.
Here is what I plan to do:
- Assign it an address on a separate subnet
- give it a public address and A record
- set up an outbound content filter that will deliver mail out of that interface if it matches the rule
My thinking is that if there are issues with the way the marketing emails are sent (i.e. they generate complaints from recipients), then the IP address of the second interface would get the poor reputation score as opposed to the primary interface.
Is there a step I am missing? Is the overall strategy valid?
Any insight would be greatly appreciated. Thanks.
After a quick review I think you missed the creation of a reversed DNS record (PTR record) for the new IP address. For SMTP traffic it's really important to have a good PTR record.
Besides that I would invite you to read carefully the topics about "virtual gateways" in you online documentation. Those are a specially created solution for your problem and if I remember right you can even use a secondary IP address on you existing interface for it.
PS: kudos for your marketing department, most of the times those guys start their e-mail cannons without even thinking about any possible side effect on the main production mail flow. :-)