Jeff.Jones.JLogger (nuget): A singleton logging component.  Simple to use, lots of flexibility.  Writes to a user-specified log and path, and optionally sends email.  Can also write logs to a SQL Server database, with optional audit log. T-SQL files included. For .NET Core 2.0+, .NET Standard 2.0+, .NET Framework 4.6.1+
Keywords: log|logging|logger|.NET|singleton|throughput|multithreaded