Visual Basic

******This is your windows application or class library project, but it should be "Public Module"******
Public Module TestModule
    Public Sub Test()
        MsgBox("Test successfully completed")
    End Sub
End Module

******Below Code to your Current Project******
Imports System.Reflection

******Use the below code at any event or funtions******
Dim Path As String = "......\"
Dim FileName As String = "XXXX.dll" 'Or "XXXX.exe"
Dim FileAssembly As Assembly = Reflection.Assembly.LoadFile(Path & FileName)
Dim ModuleName As String = "TestModule"
Dim SubName As String = "Test"
Dim RefType As Type = FileAssembly.GetType(FileAssembly.GetName.Name & "." & ModuleName)
Dim MyForm As Form = New Form
RefType.InvokeMember(SubName, BindingFlags.InvokeMethod, Nothing, MyForm, Nothing)

Dim smtpClient As New Net.Mail.SmtpClient()
        Dim mail As New Net.Mail.MailMessage()
        'create the message to be sent 
        mail.To.Add("test@test.com") ' Enter the Email of the person you want to send the mail to
        mail.From = New Net.Mail.MailAddress("username@gmail.com", "Your Display Name") ' Enter Your email address
        mail.Subject = "Test Message"
        mail.Body = "This is a test message"
        ' Prepare the client to send the above message
        smtpClient.Host = "smtp.gmail.com"
        smtpClient.EnableSsl = True
        smtpClient.Port = 587
        smtpClient.Credentials = New Net.NetworkCredential("username@gmail.com", "password") 'Enter username and password of the account , you want to use to send mail
        smtpClient.DeliveryMethod = Net.Mail.SmtpDeliveryMethod.Network
        smtpClient.Send(mail)