MSN, formerly known as Microsoft Network, was a popular instant messaging platform that allowed users to communicate with each other in real-time. While it is no longer as widely used as it once was, there are still some people who use it to keep in touch with friends and family.
If you are trying to contact someone on MSN and you are not able to get through, it is possible that they have blocked you. There are a few ways to check if someone has blocked you on MSN.