Hi experts. I have a two part question about a problem I am trying to resolve.
Before the question, I'll provide the scenario.
I am using a vendor which is basically sending out promotion materials via our domain name with the exception that they are adding their own servers and then forwarding that to customers, etc.
For example, I have domain contoso.com. They are wanting to send email from vendor.contoso.com. We house internal servers with contoso.com, but they want to send emails from @vendor.contoso.com. This is actually working to a certain extent because I have DNS entries on our external DNS servers which points to the "vendor" servers.
So, with this working as best I can describe, the piece that is not working is when a user is created on the vendor.contoso.com server as firstname.lastname@example.org this address can't seem to email the domain of @contoso.com.
In fact, no user accounts setup with @vendor.contoso.com can email @contoso.com BUT those same users emailing from @vendor.contoso.com can email all other domains successfully i.e. email@example.com
I am sure I am missing something easy, but can someone show a little pity and direct me to the water :)