1- Possuir conta de email;
2- O servidor de email permitir que a sua aplicação faça uma pesquisa de emails via POP3;
3- Criar um coneção ao servidor usando TcpClient(Servidor,Porta): no gmail é ("pop.gmail.com",995)
4- Efectuar login de utilizador com email e password;
5- Pesquisar email usando no servidor.
O login e a pesquisa de email é feita por meio de comandos enviados ao servidor.
Um exemplo bem básico:
Dim POP3 As TcpClient = Nothing
Dim nt As NetworkStream = Nothing
Dim slt As SslStream = Nothing
Dim rs As StreamReader = Nothing
Private Function LoginServidor() As Boolean
If Not POP3 Is Nothing AndAlso POP3.Connected Then POP3.Close()
Try
POP3 = New TcpClient(txtServer.Text, Val(cboPorta.Text))
Catch ex As Exception
MsgBox(ex.Message)
Return False
End Try
nt = POP3.GetStream
slt = New SslStream(nt)
Try
slt.AuthenticateAsClient(txtServer.Text)
Catch ex As Exception
MsgBox(ex.Message)
Return False
End Try
rs = New StreamReader(slt)
Dim R As String = rs.ReadLine() 'Descrição do servidor
ListBox1.Items.Add(R)
R = SendCommand("USER " & txtUser.Text)
ListBox1.Items.Add(R)
R = SendCommand("PASS " & txtPwd.Text)
ListBox1.Items.Add(R)
Return True
End Function
Private Sub LogoutServidor()
Dim rs As StreamReader = New StreamReader(slt)
Dim R As String = SendCommand("QUIT ")
End Sub
Private Sub ListarEmails()
ListBox1.Items.Clear()
ListBox2.Items.Clear()
LoginServidor()
Dim R As String
R = SendCommand("STAT ") 'numero de mensagens
ListBox1.Items.Add(R)
Dim X() As String = R.Split(" ")
ListBox2.Items.Clear()
For I As Integer = 1 To Val(X(1))
R = SendCommand("LIST " & I)
ListBox2.Items.Add(R)
Next
End Sub
Function SendCommand(ByVal Server_Command As String) As String
Server_Command = Server_Command + vbCrLf
Dim B() As Byte = System.Text.Encoding.ASCII.GetBytes(Server_Command.ToCharArray())
slt.Write(B, 0, B.Length)
Return rs.ReadLine()
End Function
