I recently updated it so that it targets .NET Standard 2.0 and also fixed the namespaces for its companion projects so that they are all under PostalNET. Current version for all projects is 1.2.0.
In a nutshell, Postal.NET publishes messages to channels and topics, either synchronously or asynchronously, and interested parties can subscribe to these.
Besides the core Postal.NET project, there are a few others:
I still need to write unit tests, but there are many samples available that hopefully will be enough to get you started. If you have interest, please have a look and share your thoughts, either here or by creating issues in GitHub!