I’ve a virtualmin installed on a CentOS 6.5, this server hosts a lot of domains of my customers. Recently I noticed an increasing number of attacks for sending spam in one of my host, and my customer doesn’t know where to patch his code for fixing the bug.
Looking at the queues of postfix I noticed that senders of these emails are @hostetdomain.com so I’d like to allow access to postfix only to specific users like alloweduser@hosteddomain1.com, alloweduser@hosteddomain2.com, and so on…
Is there something similar in virtualmin?
Thank you