Hi Andrew. If you wanted to add a 2nd domain and have it use the same IP as the first all you need to do is simply add the domain. If you wanted to have the 2nd domain use it's own IP, then you would need to either get a 2nd NIC or bind more IPs to the first NIC. As for your IIS question, you would not need to add an additional entry in IIS for the 2nd domain. I hope I'm understanding this correctly. Please let me know if you have additional questions. Thanks!

I had a domain (let's call it XYZ) and then added a new domain ABC.  Even though the emails were addressed to xxx@xyz.com, ABC was first in the list alphabetically and was sticking it's nose into the email receive.  It then tried to forward the email to XYZ, but that required a user/pass for SMTP forwarding so the emails would bounce.  I had to go the 2nd NIC and IP route to get things to work correctly

Andrew, this is not making sense to me unfortunately. What was the end goal that you wanted to accomplish?

Had 1 domain that was working for over a year.  Wanted to add a 2nd domain.  You suggested that I simply add the 2nd domain, but when I did that without adding a 2nd NIC and IP, the new domain was intercepting emails destined for the original domain and causing issues.

Andrew,

  Here is the KB that tells you how to add a domain :

https://portal.smartertools.com/kb/a2884/add-a-domain-in-smartermail.aspx?KBSearchID=789580 

   It is that way for the 1st, 2nd, 3rd, etc..

   I assume you have a licensed copy of SmarterMail and not the free version, as the free one only allows one domain.

   If you point both domains to the same IP address, MX records, it should delivery mail to the 1st domain when sending to @xyz, and when sending to @abc it should delivery mail to the 2nd domain.  If you were to configure MX records pointing to that same IP for a 3rd domain, when sending to that domain lets call it @qrs, it should bounce saying relay denied or user unknown, as that domain isn't setup on your mail server.

  There should be no way @xyz and @abc accept mail for each other, unless a domain alias was added to them, it would accept any @domain.com if the alias was setup as it.

   There must be some type of configuration issue that is making this do this.

Cheers,

-dave

Andrew,

I agree with Linda and David that this definitely doesn't sound like normal SmarterMail behavior, assuming you followed the directions in the KB that David linked.  If this issue persists, I would suggest opening a support ticket so one of our technicians can take a closer look for you.