There a number of free reverse IP domain check providers on the internet. In simple terms, a reverse IP domain check will show you other domains that are hosted on the same server as you are. By entering your competitor's domain name or IP address you can gather information about their hosting service. Information about your own hosting service provider comes handy if you want to know how many other computers are sharing the same IP. There are a number of reasons for you wanting to do a reverse IP domain check.
You might be getting complaints from clients that accessing your website is slow.
Your clients' mails are tagged as spam.
One of the search engines has detected malware on and issued a warning.
You want to protect your email servers from spam and malware.
You may be in a bad neighborhood.
If your traffic is slowing down and your customers are complaining you might want to shift your hosting service or get a static IP address server for your website.
Malware is distributed by spurious IP address across various networks and your domain network might have been attacked. This means that your web hosting service is not updating and protecting the network against malware attacks.
Your email provided by the hosting service might be labelling your clienteles email as spam. In this case, you have to inform the provider that emails from your clients should not be labelled as spam. You can use the reverse-IP-domain-check tool provided by Searchenginereports.net to check if your client's domain has been labelled as 'bad' by Google and other search engines.
If you are managing an email server, your priority will be to protect it against spam and malware. When you protect your server you must also check that your clients' emails are not being blocked. Some spam protection applications do that.
Google and other search engines will warn you that your domain is in a bad neighbourhood. This means that either malware is being hosted from your network or malware has infected your hosting service.