Check if two mail servers are alive

mailalive.py

#!/usr/bin/python

import smtplib
import imaplib
import time
import random
import string

def send_mail(smtp_server, SSL, username, password, receiver, subject, body):
    to = [receiver]
    email_text = """\
    From: %s
    To: %s
    Subject: %s

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

    server = None
    if SSL:
        server = smtplib.SMTP_SSL(smtp_server, 465)
    else:
        server = smtplib.SMTP(smtp_server, 587)
        server.starttls()
    server.ehlo()
    server.login(username, password)
    server.sendmail(username, to, email_text)
    server.close()

    return True

def check_mail(imap_server, username, password, search_query):
    M = imaplib.IMAP4_SSL(imap_server)
    M.login(username, password)
    found = False
    for n in range(60):
        M.select()
        typ, data = M.search(None, 'ALL')
        for num in data[0].split():
            typ, data = M.fetch(num, '(RFC822)')
            if search_query in data[0][1]:
                found = True
                break
        if found:
            break
        time.sleep(5)
    M.close()
    M.logout()

    return found



def get_random_string(N=64):
    return ''.join(random.choice(string.ascii_lowercase + string.ascii_uppercase + string.digits) for _ in range(N))


gmail_user = 'REDACTED'
gmail_pass = 'REDACTED'
server = 'REDACTED'
user = 'REDACTED'
password = "REDACTED"

random_body = get_random_string()
print "Random body:", random_body
print "Sending from Gmail"
assert send_mail('smtp.gmail.com', True, gmail_user, gmail_pass, user, 'subject', random_body)
print "Check if mail was received"
assert check_mail(server, user, password, random_body)

random_body = get_random_string()
print "Random body:", random_body
print "Sending to Gmail"
assert send_mail(server, False, user, password, gmail_user, 'subject', random_body)
print "Check if mail was received"
assert check_mail("imap.gmail.com", gmail_user, gmail_pass, random_body)