public void Verify(
	IDataReader emails,
	string columnName
)

Public Sub Verify ( 
	emails As IDataReader,
	columnName As String
)

using System;
using System.IO;
using System.Data;
using System.Data.SqlClient;
using MailBee;
using MailBee.AddressCheck;

class Program
{
    const string SqlDataSource = @"(local)\SQLEXPRESS";
    const string SqlDatabase = "afterlogic";
    const string SqlTable = "emails";
    const string EmailColumn = "email";
    const string IdColumn = "id";

    // Set to false to see another method of reading data from data row in event handlers.
    // Also, when false, it would be much easier to understand the console output as lines
    // from different threads won't mix. Still, 'id' field should help you understand to
    // which email address certain output line corresponds, even in multi-threaded mode.
    const bool EnableMultiThreading = true;

    static SqlConnection _sqlConnection;
    static SqlDataReader _dataReader;
    static SqlCommand _cmd;

    // Gets the data from SQL database. You must have a table such as the one made by
    // AddressValidatorDemo sample project, available in "MailBee.NET Objects\Samples\WinForms"
    // folder of "My Documents" (you can find this folder by clicking "Browse WinForms Samples"
    // button in "MailBee.NET Start Menu").
    // 
    // The "emails" table needs to have at least "id" field (numeric) and "email" field
    // (nvarchar or other string type), and some rows in it.
    private static void OpenDataReader()
    {
        SqlConnectionStringBuilder connStringBuilder = new SqlConnectionStringBuilder();
        connStringBuilder.DataSource = SqlDataSource;
        connStringBuilder.InitialCatalog = SqlDatabase;

        // Change this to use SQL Server authentication.
        connStringBuilder.IntegratedSecurity = true;

        // In AddressValidatorDemo, we need MultipleActiveResultSets because we're reading and
        // writing data in the same SQL connection. But in this sample we don't write anything
        // to the SQL server. Thus, we don't need MultipleActiveResultSets functionality.

        // Should you need to write to the database, create separate SqlConnection for that
        // or uncomment the next line.

        // connStringBuilder.MultipleActiveResultSets = true;

        _sqlConnection = new SqlConnection(connStringBuilder.ConnectionString);
        _sqlConnection.Open();
        _cmd = _sqlConnection.CreateCommand();
        _cmd.CommandText = "SELECT * FROM " + SqlTable;
        _dataReader = _cmd.ExecuteReader();
    }

    private static void FreeDataReader()
    {
        if (_dataReader != null)
        {
            _dataReader.Close();
            _dataReader = null;
        }
        if (_cmd != null)
        {
            _cmd.Dispose();
            _cmd = null;
        }
        if (_sqlConnection != null)
        {
            _sqlConnection.Close();
            _sqlConnection = null;
        }
    }

    // This method will be executed for each e-mail address in the bulk,whenever it gets verified.
    // Those addresses for which we set VerifyIt to 'false' will be skipped from further verification
    // and Verified event won't occur for them. This is true for both blacklist and whitelist, in either
    // case we don't need to process the e-mail address deeper if it's already on any of these lists.
    private static void valid_Verifying(object sender, VerifyingEventArgs e)
    {
        try
        {
            // See valid_Verified for explanations.
            int id = (int)e.DataReaderRowValues[0];

            string idStr = id.ToString();

            Console.WriteLine(string.Format("{0}: {1} is being checked against blacklist.",
                idStr, e.Email));

            if (e.Email.EndsWith("@domain.com"))
            {
                // Exclude it from address checking by other methods, and forget it.
                e.VerifyIt = false;
                Console.WriteLine(string.Format("{0}: {1} removed due to blacklist hit.", idStr, e.Email));
            }

            if (e.Email.EndsWith("@server.com"))
            {
                // Exclude it from address checking by other methods, and forget it.
                e.VerifyIt = false;
                Console.WriteLine(string.Format("{0}: {1} does not checking as it's on blacklist.",
                    idStr, e.Email));
            }

            if (e.VerifyIt)
            {
                Console.WriteLine(string.Format("{0}: {1} survived blacklist check and not on whitelist.",
                    idStr, e.Email));
            }
            else
            {
                Console.WriteLine(string.Format("{0}: {1} skipped from further verification.",
                    idStr, e.Email));
            }
        }
        catch (Exception ex)
        {
            // At least for debug purposes, it makes sense to catch all exceptions in
            // event handlers as uncaught exceptions here don't cause the app to crash.
            // Without this try/catch, it could be quite hard to understand what went wrong
            // as you'd see no indication of a problem, the event handler would silently
            // die in the middle but the app itself would continue.
            Console.WriteLine(ex.ToString());
        }

        if (!EnableMultiThreading)
        {
            // See valid_Verified for explanations.
            Console.WriteLine();
        }
    }

    // All those e-mail addresses which passed Verifying event handler then get validated,
    // and the validation results (which can be both successful or negative) will be delivered
    // to the application through Verified event handler.
    private static void valid_Verified(object sender, VerifiedEventArgs e)
    {
        try
        {
            int id;

            if (EnableMultiThreading)
            {
                // Demonstrate taking 'id' field. Unlike DataTable, IDataReader does not always permit
                // access to a data row for more than once (which happens when MailBee reads data from it).
                // Luckily, MailBee saves the data row it has read, for later use. That's how you can use it.
                id = (int)e.DataReaderRowValues[0];

                // Or, if we didn't know that 'id' is column #0, we could find it by name:
                id = (int)e.DataReaderRowValues[Array.IndexOf(e.DataReaderColumnNames, "id")];
            }
            else
            {
                // Who said that it's not possible to read from any IDataReader any number of times? Actually,
                // SqlDataReader allows us to read a current row as many times as we want. The only issue is
                // that when the app is multi-threaded, another thread may already advance the reader to the
                // next position and we won't have right data here. But when there is only one thread using
                // the data reader, it's not a problem to read directly from it.
                // 
                // Note that it's always safe to use reading from DataReaderRowValues. Just in case if for
                // some reason your app is single-threaded and for a very special reason you need to access
                // IDataReader directly, you now know how to do it.
                id = (int)_dataReader.GetValue(0);

                // Or by name.
                id = (int)_dataReader.GetValue(_dataReader.GetOrdinal("id"));
            }

            string idStr = id.ToString();

            // That's where we display the determined validation level at which the process failed, or OK.
            Console.WriteLine(string.Format("{0}: email={1}, result={2}",
                idStr, e.Email, e.Result.ToString()));

            if (e.Reason != null)
            {
                Console.WriteLine(string.Format("{0}: Reason is: {1}", idStr, e.Reason.Message));
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.ToString());
        }

        if (!EnableMultiThreading)
        {
            // Adding empty lines for clarity at the end of an event handler (to visually separate
            // processing of individual e-mail addresses) makes sense only in single-threaded mode.
            // When multi-threading is on, output from different thread mixes and makes inserting
            // empty lines useless.
            Console.WriteLine();
        }
    }

    static void Main(string[] args)
    {
        EmailAddressValidator valid = new EmailAddressValidator("MN110-0123456789ABCDEF-0123");

        // To perform DNS MX lookup queries, we need some DNS servers for that.
        valid.DnsServers.Autodetect();

        // Logging into a file is not required for the component to work
        // but helpful for debugging and understanding things under the hood.
        valid.Log.Enabled = true;
        valid.Log.Filename = @"C:\Temp\log.txt";
        valid.Log.Clear();

        // Subscribe to events.
        valid.Verifying += new VerifyingEventHandler(valid_Verifying);
        valid.Verified += new VerifiedEventHandler(valid_Verified);

        if (EnableMultiThreading)
        {
            valid.MaxThreadCount = -1;
        }

        try
        {
            OpenDataReader();

            // Run the verification in multi-threaded or single-threaded mode
            // (adjust EnableMultiThreading const to change the mode).
            valid.Verify(_dataReader, EmailColumn);
        }
        finally
        {
            FreeDataReader();
        }
    }
}

Imports System.IO
Imports System.Data
Imports System.Data.SqlClient
Imports MailBee
Imports MailBee.AddressCheck

Class Program
    Const SqlDataSource As String = "(local)\SQLEXPRESS"
    Const SqlDatabase As String = "afterlogic"
    Const SqlTable As String = "emails"
    Const EmailColumn As String = "email"
    Const IdColumn As String = "id"

    ' Set to false to see another method of reading data from data row in event handlers.
    ' Also, when false, it would be much easier to understand the console output as lines
    ' from different threads won't mix. Still, 'id' field should help you understand to
    ' which email address certain output line corresponds, even in multi-threaded mode.
    Const EnableMultiThreading As Boolean = True

    Shared _sqlConnection As SqlConnection
    Shared _dataReader As SqlDataReader
    Shared _cmd As SqlCommand

    ' Gets the data from SQL database. You must have a table such as the one made by
    ' AddressValidatorDemo sample project, available in "MailBee.NET Objects\Samples"
    ' folder of "My Documents" (you can find this folder by clicking "Browse WinForms Samples"
    ' button in "MailBee.NET Start Menu").
    '
    ' The "emails" table needs to have at least "id" field (numeric) and "email" field
    ' (nvarchar or other string type), and some rows in it.
    Private Shared Sub OpenDataReader()
        Dim connStringBuilder As New SqlConnectionStringBuilder()
        connStringBuilder.DataSource = SqlDataSource
        connStringBuilder.InitialCatalog = SqlDatabase

        ' Change this to use SQL Server authentication.
        connStringBuilder.IntegratedSecurity = True

        ' In AddressValidatorDemo, we need MultipleActiveResultSets because we're reading and
        ' writing data in the same SQL connection. But in this sample we don't write anything
        ' to the SQL server. Thus, we don't need MultipleActiveResultSets functionality.

        ' Should you need to write to the database, create separate SqlConnection for that
        ' or uncomment the next line.

        ' connStringBuilder.MultipleActiveResultSets = true;

        _sqlConnection = New SqlConnection(connStringBuilder.ConnectionString)
        _sqlConnection.Open()
        _cmd = _sqlConnection.CreateCommand()
        _cmd.CommandText = "SELECT * FROM " & SqlTable
        _dataReader = _cmd.ExecuteReader()
    End Sub

    Private Shared Sub FreeDataReader()
        If _dataReader IsNot Nothing Then
            _dataReader.Close()
            _dataReader = Nothing
        End If
        If _cmd IsNot Nothing Then
            _cmd.Dispose()
            _cmd = Nothing
        End If
        If _sqlConnection IsNot Nothing Then
            _sqlConnection.Close()
            _sqlConnection = Nothing
        End If
    End Sub

    ' This method will be executed for each e-mail address in the bulk,whenever it gets verified.
    ' Those addresses for which we set VerifyIt to 'false' will be skipped from further verification
    ' and Verified event won't occur for them. This is true for both blacklist and whitelist, in either
    ' case we don't need to process the e-mail address deeper if it's already on any of these lists.
    Private Shared Sub valid_Verifying(sender As Object, e As VerifyingEventArgs)
        Try
            ' See valid_Verified for explanations.
            Dim id As Integer = CInt(e.DataReaderRowValues(0))

            Dim idStr As String = id.ToString()

            Console.WriteLine(String.Format("{0}: {1} is being checked against blacklist.", idStr, e.Email))

            If e.Email.EndsWith("@domain.com") Then
                ' Exclude it from address checking by other methods, and forget it.
                e.VerifyIt = False
                Console.WriteLine(String.Format("{0}: {1} removed due to blacklist hit.", idStr, e.Email))
            End If

            If e.Email.EndsWith("@server.com") Then
                ' Exclude it from address checking by other methods, and forget it.
                e.VerifyIt = False
                Console.WriteLine(String.Format("{0}: {1} does not checking as it's on blacklist.", idStr, _
                    e.Email))
            End If

            If e.VerifyIt Then
                Console.WriteLine(String.Format("{0}: {1} survived blacklist check and not on whitelist.", _
                    idStr, e.Email))
            Else
                Console.WriteLine(String.Format("{0}: {1} skipped from further verification.", idStr, e.Email))
            End If
        Catch ex As Exception
            ' At least for debug purposes, it makes sense to catch all exceptions in
            ' event handlers as uncaught exceptions here don't cause the app to crash.
            ' Without this try/catch, it could be quite hard to understand what went wrong
            ' as you'd see no indication of a problem, the event handler would silently
            ' die in the middle but the app itself would continue.
            Console.WriteLine(ex.ToString())
        End Try

        If Not EnableMultiThreading Then
            ' See valid_Verified for explanations.
            Console.WriteLine()
        End If
    End Sub

    ' All those e-mail addresses which passed Verifying event handler then get validated,
    ' and the validation results (which can be both successful or negative) will be delivered
    ' to the application through Verified event handler.
    Private Shared Sub valid_Verified(sender As Object, e As VerifiedEventArgs)
        Try
            Dim id As Integer

            If EnableMultiThreading Then
                ' Demonstrate taking 'id' field. Unlike DataTable, IDataReader does not always permit
                ' access to a data row for more than once (which happens when MailBee reads data from it).
                ' Luckily, MailBee saves the data row it has read, for later use. That's how you can use it.
                id = CInt(e.DataReaderRowValues(0))

                ' Or, if we didn't know that 'id' is column #0, we could find it by name:
                id = CInt(e.DataReaderRowValues(Array.IndexOf(e.DataReaderColumnNames, "id")))
            Else
                ' Who said that it's not possible to read from any IDataReader any number of times? Actually,
                ' SqlDataReader allows us to read a current row as many times as we want. The only issue is
                ' that when the app is multi-threaded, another thread may already advance the reader to the
                ' next position and we won't have right data here. But when there is only one thread using
                ' the data reader, it's not a problem to read directly from it.
                '
                ' Note that it's always safe to use reading from DataReaderRowValues. Just in case if for
                ' some reason your app is single-threaded and for a very special reason you need to access
                ' IDataReader directly, you now know how to do it.
                id = CInt(_dataReader.GetValue(0))

                ' Or by name.
                id = CInt(_dataReader.GetValue(_dataReader.GetOrdinal("id")))
            End If

            Dim idStr As String = id.ToString()

            ' That's where we display the determined validation level at which the process failed, or OK.
            Console.WriteLine(String.Format("{0}: email={1}, result={2}", idStr, e.Email, e.Result.ToString()))

            If e.Reason IsNot Nothing Then
                Console.WriteLine(String.Format("{0}: Reason is: {1}", idStr, e.Reason.Message))
            End If
        Catch ex As Exception
            Console.WriteLine(ex.ToString())
        End Try

        If Not EnableMultiThreading Then
            ' Adding empty lines for clarity at the end of an event handler (to visually separate
            ' processing of individual e-mail addresses) makes sense only in single-threaded mode.
            ' When multi-threading is on, output from different thread mixes and makes inserting
            ' empty lines useless.
            Console.WriteLine()
        End If
    End Sub

    Shared Sub Main(args As String())
        Dim valid As New EmailAddressValidator("MN110-0123456789ABCDEF-0123")

        ' To perform DNS MX lookup queries, we need some DNS servers for that.
        valid.DnsServers.Autodetect()

        ' Logging into a file is not required for the component to work
        ' but helpful for debugging and understanding things under the hood.
        valid.Log.Enabled = True
        valid.Log.Filename = "C:\Temp\log.txt"
        valid.Log.Clear()

        ' Subscribe to events.
        AddHandler valid.Verifying, New VerifyingEventHandler(AddressOf valid_Verifying)
        AddHandler valid.Verified, New VerifiedEventHandler(AddressOf valid_Verified)

        If EnableMultiThreading Then
            valid.MaxThreadCount = -1
        End If

        Try
            OpenDataReader()

            ' Run the verification in multi-threaded or single-threaded mode
            ' (adjust EnableMultiThreading const to change the mode).
            valid.Verify(_dataReader, EmailColumn)
        Finally
            FreeDataReader()
        End Try
    End Sub
End Class