Create a multipart email message, send to multiple recipients.

multipart_email_example.py

#!/usr/bin/env python2.7

import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.base import MIMEBase
from email import Encoders

msg = MIMEMultipart()
msg['Subject'] = "Greets from Bryan"
msg['From'] = "bryan@zeebox.com"
msg['To'] = "bryan@zeebox.com"

from_user  = "from@hostname"
to_users =  ["to@hostname", "to@hostname2",]

part = MIMEBase('spreadsheet','text/csv')
part.set_payload("1,2,3,4,5\n2,4,6,8,10")
Encoders.encode_base64(part)
part.add_header('Content-Disposition','attachment; filename="data.csv"')
msg.attach(part)

part2 = MIMEText("A text message")
Encoders.encode_base64(part2)
msg.attach(part2)

s = smtplib.SMTP('localhost')
s.sendmail(from_user, to_users, msg.as_string())
s.quit()