For legacy reason, we set up our Groupwsie with 2 domain, the old one and the new one. Groupwise accept email from both old and new adresses. The "default" domain is the new one, and outgoing emails are sent using the new domain.

When we try to use an internal multifonction printer that allow send-to-email, when we use the new addresses as destination, it says "Relaying denied", but it works using the old addresses.

It's not going thru any anti-spam, which only protect from the internet.

On the internal DNS, both domains are configured and point to the same server. Ex: and

Both domains have entries on the DNS as MX, with different priorities

Any idea why?