[deanhills]

[...]

Imagine you are running a hosting company and someone abuses your IP space by spamming thousands of mail inboxes with a overall of millions of spam mails. This would get you listed on pretty much all of the blacklists. In the worst case you get the whole IP space listed and the datacenter where you got the hardware and IP space from won't be happy. They will decide to cancel the contract with you. Out of the sudden the plug in your IP space is pulled. Clients demand their money back, start PayPal and CC disputes and run away. Farewell "your hosting company name here".


Users themselves should also care of course. When I got VPSs before I performed blacklists checks and made sure I don't run anything that might cause the issues. Then I went to the blacklist sites and requested delisting. In most cases successfully. Some blacklists can be really hard to get off because they only accept removal requests from the owners of the IP blocks or won't remove a single IP address on request if they have listed the whole range.

Thanks VERY MUCH for the detailed contribution @"Hidden Refuge".  Particularly for the information on delisting.  I was hoping there was a central place one could do it at, but now understand about checking who is doing the blocking with MX Toolbox.  Probably worth signing up with them as well, as they have a very good DNS Inspect service too.Only thing, in our case with our block, MX Toolbox didn't show Google or Microsoft blocks.  That we only discovered when people were using their e-mail system.  Hopefully it's fixed now.

You're so right about the other constraints like abusing one's IP space with spamming thousands of mail inboxes.  I guess that in its own right is an excellent reason to only keep company with high quality hosts and datacenters - that is more expensive though.  Another constraint I've also found lately is with the regional blocks.  South Africa shouldn't really be blocked as the standards by the only ISP there is - Telkom - are very strict.  Those doing "funny stuff" usually get flagged in their system pretty quickly and there is a zero tolerance for abuse.  But I guess, any one living in Africa gets brushed with the same feathers from those who are situated elsewhere in the world.  Every now and then I find I can't view a show, or get access to a Website because it is not available for people from the region I'm in for now.  Hence why I guess quite a large number of people here use VPNs.  Irony is that our ISP flags people who use VPNs probably because of the high crime rate.  So both those who are honest and dishonest are penalized by the same system.

Tonight I also learned about "failover IPs".  You probably already know about them.  OVH offers a person IPs that one can migrate to other servers, but obviously the other servers have to be owned by them too - in the same family.  Aha .... looks like Hetzner is offering it too.  It does cost extra though, so I guess this will only be used by large corporations:
https://wiki.hetzner.de/index.php/Failover/en

OVH:
https://www.ovh.com/world/dedicated-serv...ilover.xml

Kimsufi - the discount company that belongs to OVH - doesn't allow additional IPs.  I found that very intriguing. 
https://www.kimsufi.com/en/faq/

I guess as time goes one on of these days getting an IPv4 is going to be very expensive.  They're probably so heavily recycled now, cleaning IPs before one uses them is going to become a specialist field of a kind.