>Is there a way to send an E-Mail (using VB.Net 2005) directly to a recipients E-Mail server, without the need for an intermediate server?

You might need to adjust some of that:

Imports System.Net.Mail
Imports System.IO

        Public cBCC As String = ""
        Public cBCCName As String = ""
        Public cBody As String = ""
        Public cCC As String = ""
        Public cCCName As String = ""
        Public cFile As String = ""
        Public cFrom As String = ""
        Public cFromName As String = ""
        Public cPort As String = ""
        Public cSMTP As String = ""
        Public cSubject As String = ""
        Public cTo As String = ""
        Public cToName As String = ""
        Public lHtml As String = True

        ' Send an email
        Public Function SendEmail() As Boolean
            Dim lcEmailAddress As String = ""
            Dim llSuccess As Boolean = False
            Dim lnCounter As Integer = 0
            Dim loAttachment As Attachment = Nothing
            Dim loEmail As MailMessage = New MailMessage
            Dim loEmailAddress As MailAddress = Nothing
            Dim loSMTP As SmtpClient = New SmtpClient

            lcEmailAddress = cFromName + " <" + cFrom + ">"

            ' From
            Try
                loEmailAddress = New MailAddress(lcEmailAddress)
            Catch loError As Exception
                oApp.ErrorSetupControlledByTheFramework("The email " + lcEmailAddress + " is invalid.")
                Return False
            End Try

            loEmail.IsBodyHtml = lHtml
            loEmail.From = loEmailAddress

            ' To
            For lnCounter = 1 To oApp.ParmCnt(cTo)
                lcEmailAddress = oApp.GetParm(cToName, lnCounter) + " <" + oApp.GetParm(cTo, lnCounter) + ">"

                Try
                    loEmailAddress = New MailAddress(lcEmailAddress)
                Catch loError As Exception
                    oApp.ErrorSetupControlledByTheFramework("The email " + lcEmailAddress + " is invalid.")
                    Return False
                End Try

                loEmail.To.Add(loEmailAddress)
            Next

            ' CC
            If cCC.Length > 0 Then
                For lnCounter = 1 To oApp.ParmCnt(cCC)
                    lcEmailAddress = oApp.GetParm(cCCName, lnCounter) + " <" + oApp.GetParm(cCC, lnCounter) + ">"

                    Try
                        loEmailAddress = New MailAddress(lcEmailAddress)
                    Catch loError As Exception
                        oApp.ErrorSetupControlledByTheFramework("The email " + lcEmailAddress + " is invalid.")
                        Return False
                    End Try

                    loEmail.CC.Add(loEmailAddress)
                Next
            End If

            ' BCC
            If cBCC.Length > 0 Then
                For lnCounter = 1 To oApp.ParmCnt(cBCC)
                    lcEmailAddress = oApp.GetParm(cBCCName, lnCounter) + " <" + oApp.GetParm(cBCC, lnCounter) + ">"

                    Try
                        loEmailAddress = New MailAddress(lcEmailAddress)
                    Catch loError As Exception
                        oApp.ErrorSetupControlledByTheFramework("The email " + lcEmailAddress + " is invalid.")
                        Return False
                    End Try

                    loEmail.Bcc.Add(loEmailAddress)
                Next
            End If

            loEmail.Subject = cSubject
            loEmail.Body = cBody
            loSMTP.Host = cSMTP
            loSMTP.Port = cPort

            ' If we have an attachment
            If cFile.Length > 0 Then
                For lnCounter = 1 To oApp.ParmCnt(cFile)
                    loAttachment = New Attachment(oApp.GetParm(cFile, lnCounter))
                    loEmail.Attachments.Add(loAttachment)
                Next
            End If

            Try
                loSMTP.Send(loEmail)
                llSuccess = True
            Catch loError As Exception
                oApp.ErrorSetup(loError)
            End Try
            Return llSuccess
        End Function