A C# library that provides an smtp client built on top of the standard SmtpClient class which is able to serialize email messages if no network connection is available. Serialized emails are sent later if a network connection is available.
Although there isn't any real documentation existing, just use the QueuedSmtpClient the same way you would use the .NET 2.0 SmtpClient class with the following difference: the QueuedSmtpClient constructor needs an additional parameter tempFolder. This folder is used for storing emails that could not be sent because of network unavailability. If the network becomes available again and the emails can be sent, the folder is cleared.
Take a look at the EmailTester demo project to see how it works.
Enjoy using this piece of code.