PowerTCP Email Validation for .NET

private void button1_Click(object sender, EventArgs e)
{
    MessageBox.Show(doValidation("yourAddress@gmail.com"));
}

private string doValidation(string emailAddress)
{
    //Validate to the ultimate level.
    validator1.ValidationLevel = ValidationLevel.SmtpRecipient;

    //Raise the progress event for every validation step.
    validator1.VerboseProgress = true;

    //DNS settings.
    validator1.Dns.Rotateservers = false; //always start with first server
    validator1.Dns.Retries = 2; //try up to 3 times
    validator1.Dns.Timeout = 5000; //5 seconds

    //SMTP settings.
    validator1.Smtp.MailFrom = "from@myDomain.com"; //required
    validator1.Smtp.ConnectTimeout = 40000; //40 seconds
    validator1.Smtp.ReceiveTimeout = 40000; //40 seconds

    //Validate and return the result.
    ValidationState result = validator1.Validate(emailAddress);
    string description = "The validation of " + result.EmailAddress;
    description += " proceeded to the "; + result.Progress.ToString() + " level. ";
    description += (result.Exception == null)
        ? "The validation was successful."
        : "The following exception occurred: " + result.Exception.ToString();
    return description;
}

private void validator1_Progress(object sender, ProgressEventArgs e)
{
    //Record validation progress to a log.
    if (e.ValidationState.Exception == null)
        textLog.AppendText(e.ValidationState.EmailAddress + " OK: " +
            e.ValidationState.Progress.ToString() + Environment.NewLine);
    else
        textLog.AppendText(e.ValidationState.EmailAddress + " ERROR: " +
            e.ValidationState.Exception.Message + Environment.NewLine);
}

private void button1_Click(object sender, EventArgs e)
{
    doValidation("yourAddress@gmail.com");
}

private void doValidation(string emailAddress)
{
    //Validate to the ultimate level.
    validator1.ValidationLevel = ValidationLevel.SmtpRecipient;

    //Raise the progress event for every validation step.
    validator1.VerboseProgress = true;

    //DNS settings
    validator1.Dns.RotateServers = false; //always start with first server
    validator1.Dns.Retries = 2; //try up to 3 times
    validator1.Dns.Timeout = 5000; //5 seconds

    //SMTP settings
    validator1.Smtp.MailFrom = "from@yourDomain.com"; //required
    validator1.Smtp.ConnectTimeout = 40000; //40 seconds
    validator1.Smtp.ReceiveTimeout = 40000; //40 seconds

    //Validate. EndValidate event will fire with result.
    validator1.BeginValidate(emailAddress, null);
}

private void validator1_EndValidate(object sender, ValidateEventArgs e)
{
    //Examine the result.
    //For single email validation, examine the first item in the Result array.
    string result = "The validation of " + e.Result[0].EmailAddress;
    result += " proceeded to the " + e.Result[0].Progress.ToString() + " level. ";
    result += (e.Result[0].Exception == null)
        ? "The validation was successful."
        : "The following exception occurred: " + e.Result[0].Exception.ToString();

    //Pass the result to a displaying function.
    display(result);
}

private void validator1_Progress(object sender, ProgressEventArgs e)
{
    //Record validation progress to a log.
    if (e.ValidationState.Exception == null)
        textLog.AppendText(e.ValidationState.EmailAddress + " OK: " +
            e.ValidationState.Progress.ToString() + Environment.NewLine);
    else
        textLog.AppendText(e.ValidationState.EmailAddress + " ERROR: " +
            e.ValidationState.Exception.Message + Environment.NewLine);
}

private void display(string message)
{
    //Show result of validation operation.
    MessageBox.Show(message);
}

private string[] doValidation()
{
    //Validation settings.
    validator1.ValidationLevel = ValidationLevel.SmtpRecipient; //final level
    validator1.BlackList = getList(Application.StartupPath + "\\blacklist.txt");
    validator1.WhiteList = getList(Application.StartupPath + "\\whitelist.txt");
    validator1.DomainCacheTimeout = 300; //300 second (5 minute) domain cache
    validator1.Smtp.TestAccount = "qwerty1298mnbvc"; //skip known "false positives"

    //DNS settings.
    validator1.Dns.RotateServers = false; //always start with first server
    validator1.Dns.Retries = 2; //try up to 3 times
    validator1.Dns.Timeout = 5000; //5 seconds

    //SMTP settings.
    validator1.Smtp.MailFrom = "myAccount@myDomain.com"; //required
    validator1.Smtp.ConnectTimeout = 40000; //40 seconds
    validator1.Smtp.ReceiveTimeout = 40000; //40 seconds

    //Validate list.
    ValidationState[] results =
    validator1.Validate(getList(Application.StartupPath + "\\myList.txt"));

    //Return results in an array.
    string[] descriptions = new string[results.Length];
    for (int i=0; i<results.Length; i++)
    {
        descriptions[i] = "The validation of " + results[i].EmailAddress;
        descriptions[i] += " proceeded to the " + results[i].Progress.ToString();
        descriptions[i] += " level. ";
        descriptions[i] += (results[i].Exception == null)
            ? "The validation was successful."
            : "The following exception occurred: " + results[i].Exception.ToString();
    }
    return descriptions;
}

private StringCollection getList(string filename)
{
    //Read a list from a file.
    StringCollection list = new StringCollection();
    StreamReader reader = new StreamReader(filename);
    while (reader.Peek() >= 0)
        list.Add(reader.ReadLine());
    reader.Close();
    return list;
}

private void validator1_Progress(object sender, ProgressEventArgs e)
{
    //Record validation progress to a log.
    if (e.ValidationState.Exception == null)
        textLog.AppendText(e.ValidationState.EmailAddress + " OK: " +
            e.ValidationState.Progress.ToString() + Environment.NewLine);
    else
        textLog.AppendText(e.ValidationState.EmailAddress + " ERROR: " +
            e.ValidationState.Exception.Message + Environment.NewLine);
}

private void doValidation()
{
    //Validation settings.
    validator1.ValidationLevel = ValidationLevel.SmtpRecipient; //final level
    validator1.BlackList = getList(Application.StartupPath + "\\blacklist.txt");
    validator1.WhiteList = getList(Application.StartupPath + "\\whitelist.txt");
    validator1.DomainCacheTimeout = 300; //300 second (5 minute) domain cache
    validator1.Smtp.TestAccount = "qwerty1298mnbvc"; //skip known "false positives"

    //DNS settings.
    validator1.Dns.RotateServers = false; //always start with first server
    validator1.Dns.Retries = 2; //try up to 3 times
    validator1.Dns.Timeout = 5000; //5 seconds

    //SMTP settings.
    validator1.Smtp.MailFrom = "myAccount@myDomain.com"; //required
    validator1.Smtp.ConnectTimeout = 40000; //40 seconds
    validator1.Smtp.ReceiveTimeout = 40000; //40 seconds

    //Validate. EndValidate event raises with result.
    validator1.BeginValidate(getList(Application.StartupPath + "\\myList.txt"), null);
}

private void validator1_EndValidate(object sender, ValidateEventArgs e)
{
    //Examine the results.
    string[] results = new string[e.Result.Length];
    for (int i=0; i<results.Length; i++)
    {
        results[i] = "The validation of " + e.Result[i].EmailAddress;
        results[i] += " proceeded to the " + e.Result[i].Progress.ToString();
        results[i] += " level. ";
        results[i] += (e.Result[i].Exception == null)
            ? "The validation was successful."
            : "The following exception occurred: " + e.Result[i].Exception.Message;
    }

    //Pass the results to a displaying function.
    display(results);
}

private void validator1_Progress(object sender, ProgressEventArgs e)
{
    //Record validation progress to a log.
    if (e.ValidationState.Exception == null)
        textLog.AppendText(e.ValidationState.EmailAddress + " OK: " +
            e.ValidationState.Progress.ToString() + Environment.NewLine);
    else
        textLog.AppendText(e.ValidationState.EmailAddress + " ERROR: " +
            e.ValidationState.Exception.Message + Environment.NewLine);
}

private StringCollection getList(string filename)
{
    //Read a list from a file.
    StringCollection list = new StringCollection();
    StreamReader reader = new StreamReader(filename);
    while (reader.Peek() >= 0)
        list.Add(reader.ReadLine());
    reader.Close();
    return list;
}

private void display(string[] results)
{
    //Display the validation results.
    foreach (string result in results)
        textResults.AppendText(result + Environment.NewLine);
}

VB.NET Example
Private Function doValidation(ByVal emailAddress As String) As String
    'Add "Imports Dart.PowerTCP.EmailValidation" at the top
    'Validate to the final level
    Validator1.ValidationLevel = ValidationLevel.SmtpRecipient
    Validator1.Smtp.MailFrom = "myAccount@myDomain.com" 'required

    'Validate and return the result
    Dim result As ValidationState = Validator1.Validate(emailAddress)
    Dim description As String = "The validation of " + result.EmailAddress + " proceeded to the "
    description += result.Progress.ToString() + " level. "

    If (result.Exception Is Nothing) Then
       description += "The validation was successful."
    Else
       description += "The following exception occurred: " + result.Exception.ToString()
    End If
    Return description
End Function