Environment
- I have an environment with 2 HUB transport servers: hub1 and hub2. Messages from mail box server go to hub1. If message is internal, then it is routed to to the mail box server, where recipient's mail box is kept. If message contains external recipients, then it is sent to hub2 which is internet-facing.
- There is transport rule, which stops message and generates NDR to the sender if message subject contains "-Error-Stop-Message" string. As I know transport rules on hub servers are global.
- On hub2 I have custom transport agent which analyzes message content and appends message subject with the "-Error-Stop-Message" in some cases.
Issue
If message from the mailbox server is sent directly to hub2 server, then everything works fine: transport agent appends subject, transport rule agent applies transport rules, as a result message is stopped and sender receives NDR.
However, if external message is sent to hub1 server, then to hub2, agent processes message, appends subject, but transport rules are not applied - NDR is not generated and message is sent to the Internet. So it seems that transport rules are applied only once - on hub1 in this scenario (subject does not contain "-Error-Stop-Message" string on hub1, because custom transport agent is on hub2). If message with external recipients is sent from hub1 to hub2, rules are not applied on hub2, because they have already been applied on hub1 server.
Question
- Can someone explain this behavior?
- Is there a way to fire transport rules on the hub2 server (not only on hub1) if message is sent from mailbox server, then to hub1, and then to hub2?