Originally Posted by louise1966:
“I usually do my training from my home laptop, with no problem, so it does seem it is an issue with my IP. Just as a process of elimination, I tried to subscribe to a newsletter, using my email address, and managed to do so. Could it be that subscribing to a newsletter is rather generic, but logging onto my works website is more specific, and the security could be stronger? How could someone else have had my IP address, and why if they did something questionable, is it just being blacklisted now? This is the first time ever I have had this problem.”
There's no real connection between services that use your email address, and network connections based on IP addresses. The IP address could be on a blacklist from one provider, but another might not have experiences any problems.
When a device establishes a connection to an internet provider, the first thing it will do is ask for an IP address. The provider's server will look for an address that isn't currently in use, and assign it. As long as that connection remains active, the IP address will be assigned to that device. When the device disconnects, the IP address will be returned to the 'pool' waiting for the next request. When you activated your current connection it's quite possible that you were allocated an IP address that was previously used by someone who's PC has a virus and was sending Spam, or perhaps was being used to download stuff illegally.
It is also very likely that your company website will be much more picky about who's allow to connect than other more public sites.
As the other posters suggest, turning off your router for a few hours should result in it being assigned a new IP address when you next connect.