I run a Plesk server (on debian 8) with several domains on it and several of my clients use it.
Every other day Hotmail, sky protect and zen spamhaus keep listing my IP, I manually get it removed but it comes back within 2-3 days, no other spam providers seem to be picking my server up and listing it , just these 3.
I need someone with more knowledge than me to work out why i'm getting listed and help me resolve the problem.
I've got back scatter bounces turned off for domains i host, but if anyone tries to send an email to a domain not on my server then it creates a bounce back, I don't know if this is the reason for the problem or something else ?
I have SPF on all domains, I have rDNS setup for the primary domain of the server. I'm using a static IP address in a data center not a dynamic or assigned ISP address.