Sending Multiple Customized Emails Using Gmail API & Python

This repository is dedicated to show:

• How to use Python Gmail API_.
• How to send multiple automated emails with customized features.

.. image:: https://github.com/astorfi/Send-Multiple-Emails/blob/master/_img/source.gif

.. _Python Gmail API: https://developers.google.com/gmail/api/quickstart/python

========== Motivation

There are couple of questions as motivate someone to use the python API for sending customized gmail.

* What if you want to send a fixed email to multiple people at once?
* What if you want to send multiple emails to a certain individual at once?
* What if you want to send multiple emails to multiple people?
* What if you want to almost similar emails to multiple people with only changing the subject or greeting customized by their first name?

Consider the aformentioned variations, using an API to easily change the email format and content using a predefined pattern or a parsed text is of great interest. As an example, let's consider we have a .csv file which has multiple subjects with their information. Suppose we want to parse the .csv file and send an invitation email to each individual when only the initial part of the emails is different which is Dear X or Dear Y for example. Using a python interface can make life easy and come to rescue us. In this repository, the exact aforementioned example will be addressed.

============== Bigger picture

At first time the python script opens a browser to take and store Gmail credentials locally. Then by using another script, the message creation will be performed. We basically use the codes provided by google except we customize few things to parse the .csv file and write the email format.

================================================= Run the Gmail API, Installation and authorization

At first, the Gmail API must be initialized. Please refer to this link <PythonQuickstartGmailAPI_>_. After turning on the Gmail API, the Google Client Library must be installed by executing the following in the command line:

.. code:: shell

 pip install --upgrade google-api-python-client

After installation, the file code/quicksetup.py must be run for providing the credentials locally. Remember the file client_secret.json must be provided and it could be downloaded when the Gmail API is being turned.

.. _PythonQuickstartGmailAPI: https://developers.google.com/gmail/api/quickstart/python

===================== Send customized email

Now the interface is ready to go. Let's take a look and our main file code/sendmessage.py. It is the code at here <code_>_ with some minor changes. We parse the .csv file and send customized emails.

.. _code: http://stackoverflow.com/questions/37201250/sending-email-via-gmail-python

Take a look at the context of the sample .csv file:

.. code:: shell

 FirstName,LastName,EmailAddress,Company,Position
 subject_name,subject_lastname,subject_email,X Corporation,Sr. Deep Learning,

The .csv file can contain multiple lines of different individuals of information. We parse it as follows:

.. code:: python

  def sendmail(attribute):
      first_name = attribute[0]
      last_name = attribute[1]
      email = attribute[2]
      print("Sending email to {}".format(email))

      to = email
      sender = "[email protected]"
      subject = "subject"
      msgPlain = ""
      msgHtml = "Hi {},<br/>This is a test email".format(first_name)
      SendMessage(sender, to, subject, msgHtml, msgPlain)


   def main():
     with open("file.csv", "rb") as file:
          msg_reader = csv.reader(file)
          msg_reader.next()
          map(sendmail, msg_reader)

So for each individual email, we just change the name and sent it again. That's all. Seems super easy but the problem is easy when it is solved, right?

========== Final Note

Before using this codes, first just provide a simple .csv file or whatever file you want to parse, and use only your emails to make sure nothing is messed up. because the last thing you want is to send wrong emails to multiple people.