APIPA addresses (169.254.x.x) in the mail header are somewhat unsightly, this problem occurs in an Exchange DAG and can certainly lead to a problem with one or other SPAM filter. Here is part of a mail header:
The cause is an incorrect sequence of network connections. The APIPA address belongs to the "Microsoft Failover Cluster Virtual Adapter", which is installed on members of a failover cluster, i.e. also a DAG:
The adapter sequence can be changed with the nvspbind tool. Nvspbind can be downloaded here:
https://gallery.technet.microsoft.com/Hyper-V-Network-VSP-Bind-cf937850
Don't be surprised: The tool was originally developed for Hyper-V. Hyper-V clusters, like Exchange DAGs, are based on the Windows Failover Clustering feature and this is exactly where the tool comes in. It can therefore also be used for Exchange DAGs or all servers that use failover clustering.
The following command can first be used to search for the name of the network adapter:
nvspbind.exe /o ms_tcpip
This command can then be used to move the failover adapter down one position in the sequence:
nvspbind.exe /- "LAN connection* 9" ms_tcpip
These steps must be carried out on all mailbox servers that are members of a DAG. After that the problem should be gone.
