from email.message import Message
    from email.mime.text import MIMEText
    from email.mime.multipart import MIMEMultipart
    from email.charset import Charset, QP
    from email.encoders import encode_quopri

    SERVER = 'mailserver.loc'
    FROM = 'billing@' + SERVER
    TO = 'abonent1@' + SERVER

    msg = MIMEMultipart('mixed')
    msg['Subject'] = 'subject'
    msg['From'] = FROM
    msg['To'] = TO
    msg['X-Message-id'] = 'xmsg_id'

    charset = Charset('windows-1251')
    charset.header_encoding = QP
    charset.body_encoding = QP

    msg.set_charset(charset)

    att1 = MIMEText('проверка111 проверка проверка', 'plain', _charset='windows-1251')
    msg.attach(att1)
    encode_quopri(att1)

    print (msg.as_string())