Hello community,
I’ve recently noticed in Rspamd that some emails were neither from nor to any of the users listed in my Mailcow instance, so they were relayed without authentication but I haven’t set any rule in place to allow such thing.
Here is an example from the logs, none of the domains are related to my MC instance :
Any idea on how this was made possible ? The instance was created a few years ago and regularly updated.
Thank you !