Hello SBS fans,
we have had two instances of customer's (some not all) email getting bounced and then the server gets blacklisted.
We use exchange for email, and EOP for the inbound/outbound. We switched providers (ISP) and got a new outside, static ip address. The MS remote connectivity analyzer passes all tests. I changed the send and receive connectors in Exchange Online protection to the new IP and all tests pass when running the MS Remote Connectivity Analyzer. But now email is bouncing, and the server is blacklisted. Somehow the local ip of the server (192.168.2.3) responds to HELO, and hence the domain gets blacklisted.
What are we doing wrong?
eholz1
Network and Server Installs