This code tested in Visual Studio 2008 and Reporting Services from SQL Server 2005

First create a class called ReportServerCredentials.vb

Imports Microsoft.VisualBasic
Imports Microsoft.Reporting.WebForms
Imports System.Security.Principal

Public NotInheritable Class ReportServerCredentials
    Implements IReportServerCredentials

    Public ReadOnly Property ImpersonationUser() As WindowsIdentity _
            Implements IReportServerCredentials.ImpersonationUser
        Get

            'Use the default windows user.  Credentials will be
            'provided by the NetworkCredentials property.
            Return Nothing

        End Get
    End Property

    Public ReadOnly Property NetworkCredentials() As Net.ICredentials _
            Implements IReportServerCredentials.NetworkCredentials
        Get

            'Read the user information from the web.config file.
            'By reading the information on demand instead of storing
            'it, the credentials will not be stored in session,
            'reducing the vulnerable surface area to the web.config
            'file, which can be secured with an ACL.

            'User name
            Dim userName As String = _
                ConfigurationManager.AppSettings("UserName")

            If (String.IsNullOrEmpty(userName)) Then
                Throw New Exception("Missing user name from web.config file")
            End If

            'Password
            Dim password As String = _
                ConfigurationManager.AppSettings("Password")

            If (String.IsNullOrEmpty(password)) Then
                Throw New Exception("Missing password from web.config file")
            End If

            'Domain
            Dim domain As String = _
                ConfigurationManager.AppSettings("SERVERNAME")

            If (String.IsNullOrEmpty(domain)) Then
                Throw New Exception("Missing domain from web.config file")
            End If

            Return New Net.NetworkCredential(userName, password, domain)

        End Get
    End Property

    Public Function GetFormsCredentials(ByRef authCookie As System.Net.Cookie, _
                                        ByRef userName As String, _
                                        ByRef password As String, _
                                        ByRef authority As String) _
                                        As Boolean _
            Implements IReportServerCredentials.GetFormsCredentials

        authCookie = Nothing
        userName = Nothing
        password = Nothing
        authority = Nothing

        'Not using form credentials
        Return False

    End Function

End Class 

Second, add parameter key to your web.config

<appSettings>
<add key="UserName" value="UserName"/>
		<add key="Password" value="Password"/>
		<add key="SERVERNAME" value="SERVERNAME"/>
</appSettings>

And then add this line of code before calling reportserverURL in the report view page:

ReportViewer1.ServerReport.ReportServerCredentials = New ReportServerCredentials()

1. This is how you use it

Dim fileAttch = New ArrayList
fileAttch.Add("C:\test.csv")
fileAttch.Add("C:\test2.csv")
fileAttch.Add("C:\test3.csv")

sendEmail.send(your_emailHost, "no-reply@company.com", your_EmailTo, your_EmailSubject, your_EmailBody, your_EmailccTo, fileAttch)

2. Create a class called sendEmail.vb

Imports System.IO
Imports System.Net.Mail
Imports Microsoft.VisualBasic
Imports System

Public Class sendEmail

    Public Shared Sub send(ByVal smtpHost As String, ByVal fromEmail As String, ByVal toEmail As String, ByVal subject As String, ByVal body As String, ByVal cc As String, Optional ByVal AttachmentFiles As ArrayList = Nothing)
        Dim mail As New MailMessage()

        '-----------------------------------
        'Set Email Address
        '-----------------------------------
        mail.From = New MailAddress(fromEmail)

        If toEmail = "" Then
            Throw New Exception("Error: No email address to send")
        End If
        If toEmail.Contains(";") Then
            Dim emailList As String()
            emailList = toEmail.Split(";")
            For Each email As String In emailList
                mail.To.Add(email)
            Next
        Else
            mail.To.Add(toEmail)
        End If
        If cc <> "" Then
            If cc.Contains(";") Then
                Dim ccList As String()
                ccList = cc.Split(";")
                For Each ccTo As String In ccList
                    mail.CC.Add(ccTo)
                Next
            Else
                mail.CC.Add(cc)
            End If
        End If

        '-----------------------------------
        'Set Email Address Content
        '-----------------------------------
        mail.Subject = subject
        mail.IsBodyHtml = True
        mail.Body = body

        Dim i As Integer
        Dim Attachment As System.Net.Mail.Attachment

        For i = 0 To AttachmentFiles.Count - 1
            If FileExists(AttachmentFiles(i)) Then
                Attachment = New Net.Mail.Attachment(AttachmentFiles(i))
                mail.Attachments.Add(Attachment)
            End If
        Next

        '-----------------------------------
        'Set Email Address Host
        '-----------------------------------
        Dim smtp As New SmtpClient(smtpHost)
        Try
            smtp.Send(mail)
        Catch ex As Exception
            '-------------------------------------------------
            MsgBox("Error " & ex.Message)
            '-------------------------------------------------
        End Try

    End Sub

    Private Shared Function FileExists(ByVal FileFullPath As String) As Boolean
        If Trim(FileFullPath) = "" Then Return False

        Dim f As New IO.FileInfo(FileFullPath)
        Return f.Exists

    End Function

End Class

Private Function GetFirstDayOfMonth(ByVal dtDate As DateTime) As DateTime
        Dim dtFrom As DateTime = dtDate
        dtFrom = dtFrom.AddDays(-(dtFrom.Day - 1))
        Return dtFrom
    End Function

    Private Function GetLastDayOfMonth(ByVal dtDate As DateTime) As DateTime
        Dim dtTo As New DateTime(dtDate.Year, dtDate.Month, 1)
        dtTo = dtTo.AddMonths(1)
        dtTo = dtTo.AddDays(-(dtTo.Day))
        Return dtTo
    End Function

'if you put code like:
GetFirstDayOfMonth("2010-05-05") ' It will return = 2010-05-01
GetLastDayOfMonth("2010-05-05") ' It will return = 2010-05-31

    Sub SetDataTable_To_CSV(ByVal dtable As DataTable, ByVal path_filename As String, ByVal sep_char As String)
        Dim writer As System.IO.StreamWriter
        Try
            writer = New System.IO.StreamWriter(path_filename)

            Dim _sep As String = ""
            Dim builder As New System.Text.StringBuilder
            For Each col As DataColumn In dtable.Columns
                builder.Append(_sep).Append(col.ColumnName)
                _sep = sep_char
            Next
            writer.WriteLine(builder.ToString())

            For Each row As DataRow In dtable.Rows
                _sep = ""
                builder = New System.Text.StringBuilder

                For Each col As DataColumn In dtable.Columns
                    builder.Append(_sep).Append(row(col.ColumnName))
                    _sep = sep_char
                Next
                writer.WriteLine(builder.ToString())
            Next
        Catch ex As Exception

        Finally
            If Not writer Is Nothing Then writer.Close()
        End Try
    End Sub

This is how you use it

Dim dt As New DataTable
SetDataTable_To_CSV(dt, "C:\test.csv", ",")

Iron Baby, which features Margaret transforming from toddler to iron-clad superhero, has attracted 2.6 million hits so far, the Daily Mail reports.

The parody short film was directed by Margaret’s father Patrick Boivin, who is a self-taught filmmaker and former comic book creator from Montreal.

3-D artist Jocelyn Strob Simard did the special effects for the film, including making the Iron Man costume, according to the Toronto Star.

The clip starts with Margaret as a bib-wearing Tony Stark, who is transformed by her mini-armoured costume into Iron Man.

The tiny superhero flies off to fight gun-toting toy bunnies, who she destroys with laser beams fired from the palm of her hand.

Costing virtually nothing, the short film took two months to make.

Source: http://www.heraldsun.com.au

Its Saturday morning, I took this picture at 6am. Marina Bay Sands 95% completed.

create new property inside partial class:
Double click on xxxTableAdaper and it will show you behind code in .vb file of xsd file. Add this code inside Partial Public Class xxxDataTableAdapter

Namespace xxxTableAdapters
    Partial Public Class yyyTableAdapter
        Public WriteOnly Property CommandTimeout() As Integer
            Set(ByVal value As Integer)
                Dim i As Integer = 0
                While (i < Me.CommandCollection.Length)
                    If (Me.CommandCollection(i) IsNot Nothing) Then
                        Me.CommandCollection(i).CommandTimeout = value
                    End If
                    i = (i + 1)
                End While
            End Set
        End Property
    End Class
End Namespace

And how you use it, you just add 1 line of code:

            Dim dt As New DataSet1TableAdapters.AddressTableAdapter
            dt.CommandTimeout = 120
            gridview1 = dt.GetData()

Notes:
xxxTableAdapters , xxx you replace with the name of .xsd file
yyyTableAdapter you replace with the name of table adapter

This code is tested in visual studio 2008 and 2005

Custom Format Examples List:

References:
http://www.technoreader.com/SQL-Server-Date-Time-Format.aspx
http://www.sql-server-helper.com/tips/date-formats.aspx