How to Send Emails in Vb. Net Using the Outlook Library

After install 'Microsoft.Office.Interop.Outlook' nuget package, you can try the following code to send email (code from ):

Imports System.IO
Imports Outlook = Microsoft.Office.Interop.Outlook

Module Module1

Sub Main()
    Dim arrAttachFiles As List(Of String) = New List(Of String)() From {
        "the file path you want to attach (e.g. D:\Test.xlsx)" 
    }
    sendEmailViaOutlook("your email address", "email addresses you want to send", "email addresses you want to cc", "this is subject", "this is body", arrAttachFiles)

End Sub
Public Sub sendEmailViaOutlook(ByVal sFromAddress As String, ByVal sToAddress As String, ByVal sCc As String, ByVal sSubject As String, ByVal sBody As String, ByVal Optional arrAttachments As List(Of String) = Nothing)

    Try
        Dim app As Outlook.Application = New Outlook.Application()
        Dim newMail As Outlook.MailItem = CType(app.CreateItem(Outlook.OlItemType.olMailItem), Outlook.MailItem)

        If Not String.IsNullOrWhiteSpace(sToAddress) Then
            Dim arrAddTos As String() = sToAddress.Split(New Char() {";"c, ","c})

            For Each strAddr As String In arrAddTos
                If Not String.IsNullOrWhiteSpace(strAddr) AndAlso strAddr.IndexOf("@"c) <> -1 Then
                    newMail.Recipients.Add(strAddr.Trim())
                Else
                    Throw New Exception("Bad to-address: " & sToAddress)
                End If
            Next
        Else
            Throw New Exception("Must specify to-address")
        End If

        If Not String.IsNullOrWhiteSpace(sCc) Then
            Dim arrAddTos As String() = sCc.Split(New Char() {";"c, ","c})

            For Each strAddr As String In arrAddTos

                If Not String.IsNullOrWhiteSpace(strAddr) AndAlso strAddr.IndexOf("@"c) <> -1 Then
                    newMail.Recipients.Add(strAddr.Trim())
                Else
                    Throw New Exception("Bad CC-address: " & sCc)
                End If
            Next
        End If

        If Not newMail.Recipients.ResolveAll() Then
            Throw New Exception("Failed to resolve all recipients: " & sToAddress & ";" & sCc)
        End If

        If arrAttachments IsNot Nothing Then

            For Each strPath As String In arrAttachments

                If File.Exists(strPath) Then
                    newMail.Attachments.Add(strPath)
                Else
                    Throw New Exception("Attachment file is not found: """ & strPath & """")
                End If
            Next
        End If

        If Not String.IsNullOrWhiteSpace(sSubject) Then newMail.Subject = sSubject
        If Not String.IsNullOrWhiteSpace(sBody) Then newMail.Body = sBody
        Dim accounts As Outlook.Accounts = app.Session.Accounts
        Dim acc As Outlook.Account = Nothing

        For Each account As Outlook.Account In accounts

            If account.SmtpAddress.Equals(sFromAddress, StringComparison.CurrentCultureIgnoreCase) Then
                acc = account
                Exit For
            End If
        Next

        If acc IsNot Nothing Then
            newMail.SendUsingAccount = acc
            newMail.Send()
        Else
            Throw New Exception("Account does not exist in Outlook: " & sFromAddress)
        End If

    Catch ex As Exception
        Console.WriteLine("ERROR: Failed to send mail: " & ex.Message)
    End Try
End Sub
End Module

Result: