Imports Outlook = Microsoft.Office.Interop.Outlook
Public Class Form1

    Private Account As Outlook.Account

    Private olApp As Outlook.Application

    Private olSession As Outlook.NameSpace

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub

    Private Sub LoadAccount()
        Dim olAccounts As Outlook.Accounts
        olApp = New Outlook.Application()
        olSession = olApp.Session
        olAccounts = olSession.Accounts
        For Each elemento As Outlook.Account In olAccounts
            Console.WriteLine(elemento.DisplayName)
        Next
        'Account = olSession.Accounts(0)        
        Account = olSession.Accounts(1)
    End Sub
    Private Sub SendOutlookMail_3(ByVal Subject As String, ByVal Recipient As String, ByVal Message As String, Optional ByVal CC As String = "")
        LoadAccount()

        Dim item As Outlook.MailItem

        item = olApp.CreateItem(Outlook.OlItemType.olMailItem)
        item.SendUsingAccount = Account
        item.Subject = Subject
        item.Body = Message

        item.Recipients.Add(Recipient)

        item.Recipients.ResolveAll()

        item.Send()
    End Sub
    Private Sub SendOutlookMail_2(ByVal Subject As String, ByVal Recipient As String, ByVal Message As String, ByVal Originator As String, Optional ByVal CC As String = "")
        'Reference Or here is GAC path C:\Windows\assembly\GAC_MSIL\Microsoft.Office.Interop.Outlook\14.0.0.0__71e9bce111e9429c\Microsoft.Office.Interop.Outlook.dll
        Dim Outlook As New Microsoft.Office.Interop.Outlook.Application
        Dim MailItem As Microsoft.Office.Interop.Outlook.MailItem
        MailItem = Outlook.CreateItem(Microsoft.Office.Interop.Outlook.OlItemType.olMailItem)
        With MailItem
            .HTMLBody = Message
            .Subject = Subject
            'use the below to change from the default email account
            .SentOnBehalfOfName = Originator
            'you can add multiple recipients using .Add()
            .Recipients.Add(Recipient)
            'examples of other optional arguments that can be included
            .Importance = Microsoft.Office.Interop.Outlook.OlImportance.olImportanceHigh
            .Display() 'opens the email for checking prior to sending or use .Send()
        End With
    End Sub

'Non serve referenziare la libreria Microsoft.Office.Interop.Outlook.dll
    Private Sub SendOutlookMail(ByVal Subject As String, ByVal Recipient As String, ByVal Message As String, ByVal Originator As String, Optional ByVal CC As String = "")

        On Error GoTo errorHandler
        Dim oLapp As Object
        Dim oItem As Object

        oLapp = CreateObject("Outlook.application")
        oItem = oLapp.createitem(0)
        '
        With oItem
            .Subject = Subject
            .SentOnBehalfOfName = Originator
            .To = Recipient
            .body = Message
            .CC = CC
            .Send()
        End With
        '
        oLapp = Nothing
        oItem = Nothing
        '

        Exit Sub

errorHandler:
        oLapp = Nothing
        oItem = Nothing
        MessageBox.Show("Notification failed; check that all addresses/entries are valid and try again.", "Task failure (Outlook).", MessageBoxButtons.OK, MessageBoxIcon.Stop)
        Exit Sub
    End Sub
End Class