def sendMail(listing):
    v_pb = 0

    HOST = listing[0]
    SUBJECT = listing[1]
    FROM = listing[2]

    userName = listing[3]
    passWord = listing[4]
    fileText = listing[5]

    s_email = listing[6].split()
    server = smtplib.SMTP_SSL(HOST, 465)
    server.login(userName, passWord)

    max_email = len(s_email)

    for i in s_email:
        msg = MIMEMultipart()
        msg['From'] = FROM
        msg['Subject'] = SUBJECT
        msg['To'] = str(i)
        msg.attach(MIMEText(fileText, 'plain'))
        server.send_message(msg)
        v_pb +=1

    server.quit()

class SendlerApp(App):

    def build(self):

        gl = GridLayout()

        host_txt = TextInput(multiline=False)
        sub_txt = TextInput(multiline=False)
        from_txt = TextInput(multiline=False)
        user_txt = TextInput(multiline=False)
        pass_txt = TextInput(multiline=False)
        msg_txt = TextInput(font_size=24)
        mail_txt = TextInput(font_size=24)

        btn_start = Button(text="Start",on_press=lambda *a: sendMail(
        listing=(host_txt.text, sub_txt.text, from_txt.text,   user_txt.text, pass_txt.text, msg_txt.text, mail_txt.text)))



        progress_bar = ProgressBar(max=max_email, size_hint=(1, .1)) # получить доступ к этой переменной из def sendMail(listing):
        progress_bar.value = v_pb                                    # получить доступ к этой переменной из def sendMail(listing):

        gl.add_widget(host_txt)
        gl.add_widget(sub_txt)
        gl.add_widget(from_txt)
        gl.add_widget(user_txt)
        gl.add_widget(pass_txt)
        gl.add_widget(msg_txt)
        gl.add_widget(mail_txt)
        bl2.add_widget(btn_start)

        gl.add_widget(progress_bar)

        return gl

if __name__ == '__main__':
    SendlerApp().run()