Notification service for .NET (c#) with priority queue?

Question

.NET

I can't find a ready service for sending notifications based on C#. I want ready-made classes that put notifications in the database + a separate sending service, which is based on a priority queue, with multithreading, etc., which would pick up these notifications from the database, apply templates to them and send them through the necessary channels, preferably several threads for better performance.
Also, in order to solve the problem of message templating there, simple options are described everywhere, it does not draw on a ready-made complete solution. It would also be nice if this service could work through high-performance databases or if you could connect the necessary packages and choose which database to work with.
Is there something similar somewhere? It's a common problem, but there are no solutions anywhere.

Answer 1

Another thing that would do everything by itself, make the button beautiful.
Just kidding :)
Here is a collection of modules on .NET https://github.com/quozd/awesome-dotnet#api
But I think I will have to finish the specified requirements manually.

Answer 2

There are no complete solutions because the tasks are too different. Everything in total will have to be finished by hand. Akka.Net
can be used to store notifications and process them . But to create letters, an additional library is already needed.