Hi all,

I'm having some issues sending mail to a group in Domino.

We host a system for a customer on our Domino server so we have setup a mail relay and SPF record in order to handle receiving and sending mail on their domain.

I have created a group called Group1 and placed some users from our customers NAB into this one, these users use mail domain let's call it @acme.com, at the same time in this group I also place some users from our main directory @main.com - so far so good.

I now need to send the group a mail from an external mail client to I enter the group internet address in my mail client group@acme.com and press send.

So now I can see that the server receives the incoming SMTP traffic but the only mails that goes through is to the main domain @main.com and for all users with @acme.com I receive the following error message:

DELIVERY FAILURE: Error transferring to MAIN.COM.OUTBOUND1-COM.MAILANYONE.NET; SMTP Protocol Returned a Permanent Error 550 [xxx.xxx.xx.xxx]. Please contact support for details.

I can't see why this is happening, my first thought was some authentication that files but I know it reaches the group on the server since it sends mails internally to our own Domain but can't send the messages out the our customers domain @acme.com.

Please if anyone have any ideas I would appreciate it!

Cheers
Kristian