Hope someone can help. Am trying to set it up so that e-mail to a sub domain can come in but they are failing to be delivered to our Exchange server and I cannot currently work out where the failure is occuring. I have a sub domainsub.domain.com (for example) which I have added as an accepted domain on Exchange and also updated the recipient policies on Exchange. However, inbound mail to anyone with one of these address is failing with the following:
550 5.7.1 Unable to relay
Recipient address rejected: undeliverable address: host exchange IP[Exchange IP] said: 550 5.7.1 Unable to relay (in reply to RCPT TO command); from=<Sender_Address> to=<name@sub.domain.com>
I am just trying to work out where the issue is with this.
Thanks,
D