Enviar correo con Visual Basic usando el control Winsock

Publicado: 13/Sep/2001

Este código me lo he encontrado en mi disco duro, pero no sé cómo ha llegado a él, puede que sea que alguien me lo haya enviado para colaborar o puede que yo lo haya bajado de algún sitio, pero no recuerdo cómo lo he conseguido.
Lo único que se, es que el fichero ZIP tiene fecha del 21 de Agosto del 2000, fecha que me imagino que sería en la que lo guardé en mi disco duro.

Así que si el autor lee esto o alguien que sepa quién es el autor, que me lo diga y pondré el correspondiente copyright o lo quitaré si así lo quiere... mientras tanto, aquí está el código y el fichero zip.

Con fecha 18/Sep/2001 el autor (Oleg Gdalevich) autorizó la publicación de este código.
El sitio donde está publicado es:
http://www.vbip.com/winsock/winsock_simple_sender.asp

Este link es para bajarte el código completo (vbSendMail.zip 3.23 KB)

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El código:

Private Enum SMTP_State
    MAIL_CONNECT
    MAIL_HELO
    MAIL_FROM
    MAIL_RCPTTO
    MAIL_DATA
    MAIL_DOT
    MAIL_QUIT
End Enum

Private m_State As SMTP_State
'

Private Sub cmdClose_Click()

    Unload Me

End Sub

Private Sub cmdNew_Click()

    txtRecipient = ""
    txtSubject = ""
    txtMessage = ""

End Sub

Private Sub cmdSend_Click()

    Winsock1.Connect Trim$(txtHost), 25
    m_State = MAIL_CONNECT

End Sub

Private Sub Form_Load()
    '
    'clear all textboxes
    '
    For Each ctl In Me.Controls
        If TypeOf ctl Is TextBox Then
            ctl.Text = ""
        End If
    Next
    '
End Sub

Private Sub Winsock1_DataArrival(ByVal bytesTotal As Long)

    Dim strServerResponse   As String
    Dim strResponseCode     As String
    Dim strDataToSend       As String
    '
    'Retrive data from winsock buffer
    '
    Winsock1.GetData strServerResponse
    '
    Debug.Print strServerResponse
    '
    'Get server response code (first three symbols)
    '
    strResponseCode = Left(strServerResponse, 3)
    '
    'Only these three codes tell us that previous
    'command accepted successfully and we can go on
    '
    If strResponseCode = "250" Or _
       strResponseCode = "220" Or _
       strResponseCode = "354" Then

        Select Case m_State
            Case MAIL_CONNECT
                'Change current state of the session
                m_State = MAIL_HELO
                '
                'Remove blank spaces
                strDataToSend = Trim$(txtSender)
                '
                'Retrieve mailbox name from e-mail address
                strDataToSend = Left$(strDataToSend, _
                                InStr(1, strDataToSend, "@") - 1)
                'Send HELO command to the server
                Winsock1.SendData "HELO " & strDataToSend & vbCrLf
                '
                Debug.Print "HELO " & strDataToSend
                '
            Case MAIL_HELO
                '
                'Change current state of the session
                m_State = MAIL_FROM
                '
                'Send MAIL FROM command to the server
                Winsock1.SendData "MAIL FROM:" & Trim$(txtSender) & vbCrLf
                '
                Debug.Print "MAIL FROM:" & Trim$(txtSender)
                '
            Case MAIL_FROM
                '
                'Change current state of the session
                m_State = MAIL_RCPTTO
                '
                'Send RCPT TO command to the server
                Winsock1.SendData "RCPT TO:" & Trim$(txtRecipient) & vbCrLf
                '
                Debug.Print "RCPT TO:" & Trim$(txtRecipient)
                '
            Case MAIL_RCPTTO
                '
                'Change current state of the session
                m_State = MAIL_DATA
                '
                'Send DATA command to the server
                Winsock1.SendData "DATA" & vbCrLf
                '
                Debug.Print "DATA"
                '
            Case MAIL_DATA
                '
                'Change current state of the session
                m_State = MAIL_DOT
                '
                'So now we are sending a message body
                'Each line of text must be completed with
                'linefeed symbol (Chr$(10) or vbLf) not with vbCrLf
                '
                'Send Subject line
                Winsock1.SendData "Subject:" & txtSubject & vbLf
                '
                Debug.Print "Subject:" & txtSubject
                '
                Dim varLines    As Variant
                Dim varLine     As Variant
                '
                'Parse message to get lines (for VB6 only)
                varLines = Split(txtMessage, vbCrLf)
                '
                'Send each line of the message
                For Each varLine In varLines
                    Winsock1.SendData CStr(varLine) & vbLf
                    '
                    Debug.Print CStr(varLine)
                Next
                '
                'Send a dot symbol to inform server
                'that sending of message comleted
                Winsock1.SendData "." & vbCrLf
                '
                Debug.Print "."
                '
            Case MAIL_DOT
                'Change current state of the session
                m_State = MAIL_QUIT
                '
                'Send QUIT command to the server
                Winsock1.SendData "QUIT" & vbCrLf
                '
                Debug.Print "QUIT"
            Case MAIL_QUIT
                '
                'Close connection
                Winsock1.Close
                '
        End Select

    Else
        '
        'If we are here server replied with
        'unacceptable respose code therefore we need
        'close connection and inform user about problem
        '
        Winsock1.Close
        '
        If Not m_State = MAIL_QUIT Then
            MsgBox "SMTP Error: " & strServerResponse, _
                    vbInformation, "SMTP Error"
        Else
            MsgBox "Message sent successfuly.", vbInformation
        End If
        '
    End If

End Sub

Private Sub Winsock1_Error(ByVal Number As Integer, Description As String, ByVal Scode As Long, ByVal Source As String, ByVal HelpFile As String, ByVal HelpContext As Long, CancelDisplay As Boolean)

    MsgBox "Winsock Error number " & Number & vbCrLf & _
            Description, vbExclamation, "Winsock Error"

End Sub

Espero que te sea de utilidad.

Nos vemos.
Guillermo