If you are sending an outbound message, but the message fails with this error:
"550 5.7.1 Could not find a valid Account ID (0) for the given domain(domain.com) (id: X0xxxx)"
There may be a couple situations you might see this:
The sender is using an email address with a domain that is either not subscribed on our system or not aliased to a subscription. In this case our system will reject the message. To solve this the sender will need to change their sender address to use a domain that is setup on our system.
Or, you might be forwarding a message out via our outbound system. If this is the case, your email server may be using the original sender's address (such as @gmail.com), so our system blocks the message (since the sending domain is not subscribed or aliased on our system). There are a couple steps to solve this:
Ensure you have the Smart host setup option enabled in the Outbound > Outbound settings page.
Once that is enabled, our system will allow you to forward emails on two conditions:
The envelope sender uses a domain that is subscribed/aliased, and the From address uses the original sender
The envelope sender is blank, but the From address uses a subscribed/aliased domain.
To change the sender address of a message that is being forwarded, you might be able to accomplish this by using Sender Rewrite Scheme (SRS). Here is our Postfix article about this:
Allow Postfix to Forward through Outbound Service
We do not have an article that explains how to use Sender Rewrite Scheme (SRS) in Exchange or Office 365 yet, but here's a Google search that may help:
Setting up SRS on Exchange (Google search)