import smtplib

gmail_user = "username@gmail.com"
gmail_password = "******"

sent_from = gmail_user
file = open("email_list.txt", "r")
to = file.readlines()
subject = "SUBJECT OF E-MAIL"
body = "BODY OF E-MAIL"

email_text = """
From: %s
To: %s
Subject: %s

%s
""" % (sent_from, ", ".join(to), subject, body)

try:
    server = smtplib.SMTP_SSL('smtp.gmail.com', 465)
    server.ehlo()
    server.login(gmail_user, gmail_password)
    server.sendmail(sent_from, to, email_text)
    server.close()

    print("Email sent!")
except:
    print("Error!")