This is a contact form app. E-mail messages are sent in background by using an ASP.NET Core Hosted Service in a fire-and-forget fashion.

Check out the actual Hosted Service implementation in the code file HostedServices/EmailSenderHostedService.cs.

This code is NOT production-ready. It just illustrates how to implement and register a Hosted Service for sending e-mails. Some messages might be lost since this webapp does not implement a retry mechanism nor it uses a persistent storage.

Edit the appsettigs.json file with your SMTP server data. Then, just run the application by typing dotnet run. The .NET Core SDK 2.0 (or greater) must be installed in your system. Fill in the form and hit the Send button.