Sending random images via smtplib [SOLVED]

[AlphaInc]

Hello everybody,

I have a python-Script which sends E-Mails to my main account which I use as a notification method for birthdays.
Now I want to expand on that by adding an attachment (image).

Also, when possible, I like to send images from a pool of 5 pictures. Every time the script is started it should send one random image but without repeating them. When the script has been executed 5 times (all 5 images have been sent) it should reset and sent the images again (but in a new random order).
How can you do so?

This is my script so far:

#!/usr/bin/env python3

import smtplib
import time

f1 = open("../index/mail.txt","r")
mail = f1.read() [:-1]
f1.close()

f2 = open("../index/passwd.txt","r")
passwd = f2.read() [:-1]
f2.close()

f3 = open("../index/receiver.txt","r")
receiver = f3.read() [:-1]
f3.close()

#Email Variables
SMTP_SERVER = 'smtp.gmail.com'  #Email Server (don't change!)
SMTP_PORT = 587                 #Server Port (don't change!)
GMAIL_USERNAME = mail           #change this to match your gmail account
GMAIL_PASSWORD = passwd         #change this to match your gmail password

class Emailer:
    def sendmail(self, recipient, subject, content):

        #Create Headers
        headers = ["From: " + GMAIL_USERNAME, "Subject: " + subject, "To: " + recipient,
                   "MIME-Version: 1.0", "Content-Type: text/html"]
        headers = "\r\n".join(headers)

        #Connect to Gmail Server
        session = smtplib.SMTP(SMTP_SERVER, SMTP_PORT)
        session.ehlo()
        session.starttls()
        session.ehlo()

        #Login to Gmail
        session.login(GMAIL_USERNAME, GMAIL_PASSWORD)

        #Send Email & Exit
        msg = (headers + "\r\n\r\n" + content).encode('utf-8')
        session.sendmail(GMAIL_USERNAME, recipient, msg)
        session.quit

sender = Emailer()

sendTo = receiver

emailSubject = "Subject"
emailContent = "Content"

#Sends an email to the "sendTo" address with the specified "emailSubject" as the subject and "emailConten$
sender.sendmail(sendTo, emailSubject, emailContent)