Can anyone explain this email sending code to me.

Hi

I have received the responsibility of maintain and further development of a existing web application. For this reason I am studying the codes behind it. As I am a novice to VB.net I am struggling very hard. 

Below is the code of sending email . The code is working fine in its current area.  But In this code I don't see any smtp client credentials and  smtp port .  How this code is working without the client port and client credentials

Imports System.Web.Configuration
Imports System.Net
Imports System.Net.Mail

Public Sub Send()
            Dim Message As New System.Net.Mail.MailMessage
            With Message
                .Subject = Me.Subject
                .Body = Me.Body
                .From = EmailStringToMailAddress(Me.MailFrom)

                AddAddressString(Me.MailTo, .To)
                AddAddressString(Me.MailCC, .CC)
                AddAddressString(Me.MailBCC, .Bcc)
                .IsBodyHtml = True
                If Not IsNothing(Attachments) Then

                    If Attachments.Length > 0 Then

                        For Each FileName As String In Split(Attachments, ";")

                            FileName = Replace(FileName, "~/", System.Web.Hosting.HostingEnvironment.ApplicationVirtualPath & "/")

                            If FileName.StartsWith("/") Then
                                FileName = System.Web.HttpContext.Current.Server.MapPath(FileName)
                            End If

                            Try
                                Message.Attachments.Add(New System.Net.Mail.Attachment(FileName))
                            Catch
                                System.Web.HttpContext.Current.Response.Write(FileName & " could not be found")                         
                            End Try

                        Next

                    End If

                End If

            End With

            Try
                Dim Client As New System.Net.Mail.SmtpClient

                With Client

                   If WebConfigurationManager.AppSettings("smtpserver").Length > 0 Then

                        .DeliveryMethod = Net.Mail.SmtpDeliveryMethod.SpecifiedPickupDirectory 
                        .PickupDirectoryLocation = "c:/outbox/"
                        .Host = WebConfigurationManager.AppSettings("smtpserver")

                    Else
                        .DeliveryMethod = Net.Mail.SmtpDeliveryMethod.PickupDirectoryFromIis

                    End If

                    .Send(Message)

                End With

            Catch Ex As Exception

                _error = Ex.Message

            End Try

            Dim Query As String = ""
            Query &= vbCrLf & "IF @id != 0"
            Query &= vbCrLf & "BEGIN"
            Query &= vbCrLf & "    UPDATE emaillog SET error=@error, mailfrom=@mailfrom, mailto=@mailto, mailcc=@mailcc, mailbcc=@mailbcc, subject=@subject, emailcontentid=@emailcontentid WHERE id=@id;"
            Query &= vbCrLf & "    SELECT @id;"
            Query &= vbCrLf & "END"
            Query &= vbCrLf & "ELSE"
            Query &= vbCrLf & "BEGIN"
            Query &= vbCrLf & "    INSERT INTO emaillog (error, mailfrom, mailto, mailcc, mailbcc, subject, body, emailcontentid) VALUES (@error, @mailfrom, @mailto, @mailcc, @mailbcc, @subject, @body, @emailcontentid);"
            Query &= vbCrLf & "    SELECT SCOPE_IDENTITY();"
            Query &= vbCrLf & "END"
            _id = Core.DB.GetInteger(WebConfigurationManager.ConnectionStrings("logConnectionString").ConnectionString, Query, _
                Core.DB.SIP("id", _id), _
                Core.DB.SIP("error", _error), _
                Core.DB.SIP("emailcontentid", Me.ContentID), _
                Core.DB.SIP("mailfrom", IIf(IsNothing(Me.MailFrom) = True, "", Me.MailFrom)), _
                Core.DB.SIP("mailto", IIf(IsNothing(Me.MailTo) = True, "", Me.MailTo)), _
                Core.DB.SIP("mailcc", IIf(IsNothing(Me.MailCC) = True, "", Me.MailCC)), _
                Core.DB.SIP("mailbcc", IIf(IsNothing(Me.MailBCC) = True, "", Me.MailBCC)), _
                Core.DB.SIP("subject", IIf(IsNothing(Me.Subject) = True, "", Me.Subject)), _
                Core.DB.SIP("body", IIf(IsNothing(Me.Body) = True, "", Me.Body)))
End Sub

I want to understand this code cause I want to implement this code in to the other web forms in the application as well.

I will really appreciate if you help me to understand this code.

Thanks