This is for a shared server for which I am the admin. It's semi-managed elsewhere for hardware, but software issues usually fall on me.
As of yesterday, two clients have reported the same problem. Several of their customers from overseas have tried emailing them, but get the following error:
This has been reported from one email sender from Brazil, another from Hong Kong, and another from Malaysia. Remember, these are external people getting an error when emailing my client, but the client has no error when emailing back. Running a trace through WHM returns with no errors.
I don't see any of the IPs listed in cpHulk or CSF. As a test, I completely disabled CSF for this server and asked the one from Malaysia to try again, but he's still getting the same error.
Presumably, this problem didn't exist until yesterday.
Any suggestions on what the problem might be, if it's not CSF or cpHulk?
As of yesterday, two clients have reported the same problem. Several of their customers from overseas have tried emailing them, but get the following error:
Code:
550 Your host is not allowed to connect to this server.
Connection to host lost.
I don't see any of the IPs listed in cpHulk or CSF. As a test, I completely disabled CSF for this server and asked the one from Malaysia to try again, but he's still getting the same error.
Presumably, this problem didn't exist until yesterday.
Any suggestions on what the problem might be, if it's not CSF or cpHulk?