Forum Discussion
Securing mailflow in the hybrid configuration
Here's the picture.
I'm talking about the red line which shows the SMTP between EO and on-prem. Basicaly We need to set up the receive connector on the Edge servers to not accepts emails from any other tenant exepct our. Is that clear?
If your MX is pointing to on-prem, internet senders and O365 users outside of your tenant will not be hitting the connector. Generally speaking, you can restrict the connector to only specific domain, or even scope it based on a transport rule (for example with the "sender is internal" condition), but it should not be needed in your scenario.
I wish I could agree with you :) We've set up a custom outbound connector in another tenant which points to the Edge server. At this case emails are delivered. Is it possible to filter inbound messages only from a specific domain?
- Receive connectors can't filter by domain. You're also already filtering by domain by way of "Accepted Domains".
If someone tries to send you an email to a domain that's not on that list, exchange is going to reject it regardless whether it's coming from.
