Knowledge base

var verifier = new EmailVerifier();
var result = verifier.Verify("john@example.org", VerificationLevel.Mailbox);

if (result.IsSuccess)
{
    Console.WriteLine("Mailbox verification test succeeded!");
}
else
{
    // The test failed. Let's see why...

    if (result.IsSyntaxFailure)
    {
        // The e-mail address is not syntactically valid
        // TODO: Discard this address immediately
    }
    else if (result.IsTimeoutFailure)
    {
        // It failed because of a timeout, thus it could be valid
        // TODO: Save a reference to this address for future retries
    }
    else if (result.IsNetworkFailure)
    {
        // It failed because of a network failure: chances are high that this
        // address is not valid!

        // TODO: Discard this address or save it for future retries
    }
                
    // TODO: Test fo other failure types and act accordingly

	switch (result.Status)
	{
		// case ...
	}
}