My office recently had to set up an emergency wireless modem, giving us a new public IP address. We only have this one IP, whereas before we had several static IPs, and one of these led to our exchange server.
Our incoming email doesn't work. Senders are being given rejection messages that look like:
Delivery to the following recipient failed permanently:
Technical details of permanent failure: Google tried to deliver your message, but it was rejected by the server for the recipient domain [domain].com by mailstore1.secureserver.net. [220.127.116.11].
The error that the other server returned was: 550 5.1.1 <[username]@[domain].com> Recipient not found. http://x.co/irbounce
This is odd because in our GoDaddy DNS settings mailstore1.secureserver.net isn't the primary MX. The highest priority MX record is the one that points to our internal exchange server.
I'm wondering why there isn't any error from the first attempt. Did it send it successfully? If so, then where are these emails on the exchange server? Why aren't they being sent? But if GoDaddy can't send the mail to the exchange server, why not?
I suspect this is an issue with the IP that's being given to GoDaddy. Either that, or it's an IP issue within our fortinet router which handles the virtual IPs that route mail to the exchange server.
Oddly enough, outgoing email appears to work fine.