Remember when you were in school, there was always someone that their reputation came before them and not always in a good way..
Well much like school the internet has the same thing and a much longer memory.
If your PC or mail server gets hacked and sends tens of thousands of emails the public IP address of your internet connection will get a bad reputation to the point other systems may not accept email from you.
Your public facing Website may get hacked and hidden pages are created that can be used for delivering malicious content via the emails I have warned you not to open.
These types of issues can be very harmful to your Internet Reputation which will impact access to sites, email and a number of things you depend on daily. Many smart firewalls will now simply block connections to sites purely based on reputation scoring.
Sites such as the below are used to check how your IP Address, Email Domain and WebPages appear to the outside world, many you can subscribe to for automatic alerting if you are added and it is key to protecting your Internet Reputation;
WatchGuard Reputation Enabled Defense - Firewall based reporting & blocking for IP Addresses, Countries (Geo) and Content.
BrightCloud Threat Intelligence - Website & Content Reputation
There are lots more ways to check, this is to provide a snippet of what can prevent you accessing or emailing content.
Contact us further if you need assistance in checking your Internet Reputation - firstname.lastname@example.org