Sonicwall Security appliance
I have one domain that is unable to send email into my company.
We can communicate with them properly in our sends, but when they send inbound to my network, they get a generic bounce back coming from my Sonicwall device with no codes or details.
The sonicwall makes no record of any incoming transmission from them in the audit log.
I have added their Domain IP into my trusted networks list, as well as to the allowed list in my Sonicwall device.
I have done testing through Exchange diagnostics toolbox and all were successful-- even the test mimicking a send their email server.
I can assume the problem is on our end, as the bounceback comes from the sonicwall on our end.
I am looking for any direction as to where to look next.
All responses are appreciated.