Configuring node-specific settings
The email configuration settings are node-specific, so those system variables are not stored in the backend database, but in each node's registry.
However, most registry settings replicate by default, to ensure that the settings on secondary nodes are made from the primary node.
Sometimes it is useful to add some of these configuration settings to the replication's utility blacklist, so that you can configure the setting separately on each application node.
After blacklisting the system variable, you must login separately to each node and change its value appropriately.
Uses cases
Application administrators usually want to know what node any alerts are coming from, so they can address the issues on the specific servers, without having to look at the hidden message headers to identify through which gateways the message moved (sometimes all emails go through the same gateway, as in use case 2 below).
Solution:
Blacklist SENDER_EMAIL.
Set its value to something like "instancename-nodename@company.com", for example "prod-pam-001@bravurasecurity.com".
Some nodes running in different data centers may use different SMTP servers, or different credentials.
Solution: lacklist MAIL SERVER (and optionally, MAIL SERVER PORT).
Some nodes in different data centers may be managed by different teams.
Solution: Blacklist RECIPIENT EMAIL.