For sending Email to a list of receivers using python can done by using the given code. Here I am using Gmail SMTP service for this purpose (Create a separate account for this, cause it might be dangerous to use your primary email address as the Gmail might suspend you account in case of spamming).

There are 3 things required

1. Message written in text file. (sampleMessage.txt)
2. List of receivers in csv file. (listReceivers.csv)
3. Edit your Gmail account security to allow access for less secure apps by using the below link.
https://www.google.com/settings/security/lesssecureapps and select turn on.

Keep your sampleMessage.txt, listReceivers.csv and sendEmail.py file under the same directory.

The content of sampleMessage.txt is

Hi there, How are you ?

Regards,
Abhishek

The content of listReceivers.csv is

Name, Email
Abhishek, abhishek@xyz.com
Mukesh, mukesh@abc.com
Ayush, ayushBlueCoder@abc.com
.
.
.
.
.
.
Pankaj, pankaj@gmail.com

Here is the code for sending the email to the receivers (sendEmail.py)

import csv
import smtplib
from email.mime.text import MIMEText
import re

fp = open('sampleMessage.txt','rb')
msg = MIMEText(fp.read())
fp.close()

msg['Subject'] = 'Test Email'
msg['From'] = 'sender@gmail.com' #put the email address of sender

server = smtplib.SMTP('smtp.gmail.com:587')
server.starttls()
server.login(msg['From'],'xxxxxxxxxxx')  #put sender's password here 

email_data = csv.reader(open('listReceiver.csv','rb'))
email_pattern = re.compile("^.+@.+\..+$")

flag = 0

for row in email_data:
        if( email_pattern.search(row[1])):
                del msg['To']
                msg['To'] = row[1]
                try:
                        server.sendmail(msg['From'],[row[1]],msg.as_string())
                        print "Message sent to ", row[0]
                except SMTPException:
                        flag = 1
                        print "Error occoured while sending the emails"
server.quit()

if flag == 0:
        print "Messages are sent sucessfully"

Output after running the program

Message sent to  Abhishek
Message sent to  Mukesh
Message sent to  Ayush
.
.
.
.
.
Message sent to Pankaj
Messages are sent sucessfully