Day36

Day 36: Email Notifications

Instructions:

1. Open a new python file.
2. With any automated program, it is critical to create a notification system to provide details when the program is concluded. Python comes with the smtplib package in the standard library. This adds the functionality to connect to a mail client and sent mail in an automated fashion. Programs can be created to complete mail merge tasks or just send confirmation when a process is complete. The basic connectivity of smtplib only sends emails in basic text format; however, there is also functionality for receiving email or sending HTML emails.

   import smtplib
   import os
   

3. The login credentials should never be hard coded into the program or even stored as a plain text file on the system (just like this example). A better method would be to prompt the user for the password or stores the username and password as system environment variables. If the credentials are leveraged as variables in the script, make sure to clear the contents the instant it is no longer needed for added security.

   credentials = dict()
   
   with open("credentials.txt", "r") as cred:
       for line in cred:
           var, val = line.split(": ")
           credentials[var] = val.rstrip("\n")
           var = ""
           val = ""
           line = ""
   

4. Creates an SMTP object that uses the smtp address of the email client. For example, "smtp.gmail.com" would be the address for a Gmail account.

   smtpObj = smtplib.SMTP(f'smtp.{credentials["username"].split("@")[1]}', 587)
   smtpObj.ehlo()
   

5. Puts the connection to the SMTP server into TLS mode to ensure the portal is encrypted.

   smtpObj.starttls()
   

6. The .login() function is required to log into the email client. If the user is using Gmail, then an app password needs to be generated and used as the password for the login credentials.

   smtpObj.login(credentials["username"], credentials["password"])
   

7. The email is then sent while specifying the sender, receiver(s), and the contents of the message. In order to apply a subject line, the Subject: declaration is required, followed by a \n to terminate the subject line. Everything that follows is the message body.

   smtpObj.sendmail(credentials["username"], credentials["username"],
                    f"Subject: Automated Email Test\nDear {os.getlogin()},\nThis is a test of the automated email system.")
   

8. For security purposes, the credentials dictionary is cleared so the information contained cannot be pulled.

   credentials.clear()
   

9. With the email sent, the smtp object is closed with the .quit() function. This closes the connection to the email client.

   smtpObj.quit()
   

10. Update the log file with what you have learned today.