The Simple Mail Transfer Protocol (SMTP) serves as a protocol for managing email transfer through Python. This protocol is responsible for directing emails between various email servers. Operating at the application layer, it enables users to send messages to one another. Recipients access their emails utilizing either the POP (Post Office Protocol) or IMAP (Internet Message Access Protocol).
When the server is set to receive a TCP connection from a client, it starts the connection process on port 587.
Python includes a module named smtplib, which establishes an SMTP client session object that facilitates the sending of emails to an external internet server. To utilize this functionality, it is necessary to import the smtplib module through the import statement.
$ import smtplib
The SMTP class is utilized for the purpose of transferring emails. The subsequent syntax is employed to instantiate the smtplib object.
import smtplib
smtpObj = smtplib.SMTP(host, port, local_hostname)
It accepts the following parameters.
- host: It is the hostname of the machine which is running your SMTP server. Here, we can specify the IP address of the server like ( https://www.logic-practice.com ) or localhost. It is an optional parameter.
- port: It is the port number on which the host machine is listening to the SMTP connections. It is 25 by default.
- local_hostname: If the SMTP server is running on your local machine, we can mention the hostname of the local machine.
The SMTP object's sendmail function is utilized to dispatch email to the specified machine. Below is the syntax for this method.
smtpObj.sendmail(sender, receiver, message)
Python Example for Sending Email using SMTP
Let’s consider an example to illustrate the process of sending an email utilizing SMTP in Python.
#!/usr/bin/python3
import smtplib
sender_mail = '[email protected]'
receivers_mail = ['[email protected]']
message = """From: From Person %s
To: To Person %s
Subject: Sending SMTP e-mail
This is a test e-mail message.
"""%(sender_mail,receivers_mail)
try:
smtpObj = smtplib.SMTP('localhost')
smtpObj.sendmail(sender_mail, receivers_mail, message)
print("Successfully sent email")
except Exception:
print("Error: unable to send email")
Sending Email from Gmail
There are scenarios in which emails are dispatched utilizing the Gmail SMTP server. In such instances, we have the option to specify Gmail as the SMTP server rather than employing localhost on port 587.
To send an email using Gmail, the following syntax must be employed.
$ smtpObj = smtplib.SMTP("gmail.com", 587)
In this instance, it is essential to access the Gmail account utilizing the Gmail username along with the password. To facilitate this, the smtplib module offers the login function, which requires the sender's username and password as its parameters.
This could prompt your Gmail account to request permission for access to less secure applications, provided you are utilizing Gmail. You will need to enable this feature temporarily for the process to function correctly.
Python Example to Send Email from Gmail
To illustrate how to send an email using Gmail in Python, let's consider an example.
#!/usr/bin/python3
import smtplib
sender_mail = '[email protected]'
receivers_mail = ['[email protected]']
message = """From: From Person %s
To: To Person %s
Subject: Sending SMTP e-mail
This is a test e-mail message.
"""%(sender_mail,receivers_mail)
try:
password = input('Enter the password');
smtpObj = smtplib.SMTP('gmail.com',587)
smtpobj.login(sender_mail,password)
smtpObj.sendmail(sender_mail, receivers_mail, message)
print("Successfully sent email")
except Exception:
print("Error: unable to send email")
Sending HTML in Email
To format the HTML within the message, it is essential to indicate the MIME version, content-type, and character set to effectively transmit the HTML.
Python Example to Send HTML in Email
Let us consider an example to illustrate the process of sending HTML content via email using Python.
#!/usr/bin/python3
import smtplib
sender_mail = '[email protected]'
receivers_mail = ['[email protected]']
message = """From: From Person %s
To: To Person %s
MIME-Version:1.0
Content-type:text/html
Subject: Sending SMTP e-mail
<h3>Python SMTP</h3>
<strong>This is a test e-mail message.</strong>
"""%(sender_mail,receivers_mail)
try:
smtpObj = smtplib.SMTP('localhost')
smtpObj.sendmail(sender_mail, receivers_mail, message)
print("Successfully sent email")
except Exception:
print("Error: unable to send email")
