How to clear all data in MIMEBase (email module)
import smtplib
from email.MIMEMultipart import MIMEMultipart
from email.MIMEBase import MIMEBase
from email.MIMEText import MIMEText
from email.Utils import COMMASPACE, formatdate
from email import Encoders
import os

def sendMail(to, subject, text, files=[],server="smtp.gmail.com:587"):
    assert type(to)==list
    assert type(files)==list
    fro = "psaoflamand@live.com>"

    msg = MIMEMultipart()
    msg['From'] = fro
    msg['To'] = COMMASPACE.join(to)
    msg['Date'] = formatdate(localtime=True)
    msg['Subject'] = subject

    msg.attach( MIMEText(text) )
    a=0
    username = 'psaoflamand@gmail.com'
    password = 'pass'

    # The actual mail send


    smtp = smtplib.SMTP(server)
    smtp.starttls()
    smtp.login(username,password)

    for file in files:
        a+=1
        print a
        part = MIMEBase('application', "octet-stream")
        part.set_payload( open(file,"rb").read() )
        Encoders.encode_base64(part)
        part.add_header('Content-Disposition', 'attachment; filename="%s"'
                       % os.path.basename(file))
        msg.attach(part)
        if a==21:
            smtp.sendmail(fro, to, msg.as_string() )
            a=0
            print 'sent'


    smtp.quit()


sendMail(
        ["psaoflamand@live.com"],
        "hello","cheers",
        ["Thousands of one megabyte files"]