From the “Department of the bleedin’ obvious”:-
When considering, or even actually adding mail rules to your Domino server’s configuration document, always, always, always make sure that you have a backup of the Domino Directory BEFORE you start.
It seems that when you have your server configuration document opened in Edit mode, and add a server mail rule, it actually ADDs said rule to the router task of the server in question, even if you don’t save the server configuration document. Not nice ..!
No problem I hear you cry. Just disable the rule, right? Wrong! Since I didn’t actually save the test rule in question, or the server configuration document for that matter, the rule didn’t appear within the server configuration document, but did register on the server’s router task. Issuing a “set rules” from the server console confirmed the appearance of an additional, phantom mail rule.
I was caught out by this, and by my own stupidity, for:-
a.) Testing this on a production mail server (WTF was I thinking)
b.) for not having a recent backup of the Domino Directory to hand.
Whether this is a bug within our implementation of Domino Server, or a known issue with the Domino Server 8.5.X codestream, I don’t know. What I do know is that I had to restore the server configuration document from a backup, and restart the server to fix the problems caused by my “test” server mail rule.
So, the moral of this story is please don’t be an eejit and always backup before dicking about with things, no matter how insignificant they seem.