Try this soluction

<form method="POST" action="/insertenquiry/">
  {% csrf_token %}
  <!-- <label for="fname">First Name</label> -->
  <input type="text" name="firstname" class="form-control" placeholder="Your firstname" required>
  <!-- <label for="lname">Last Name</label> -->
  <input type="text" name="lastname" class="form-control" placeholder="Your lastname" required>
  <!-- <label for="email">Email</label> -->
  <input type="text" name="email" class="form-control" placeholder="Your email address" required>
  <!-- <label for="message">Message</label> -->
  <textarea name="saysomething" cols="30" rows="10" class="form-control" placeholder="Say something about us" required></textarea>

  <!-- Submit button -->
  <input type="submit" value="SEND ENQUIRY">

  <!-- The actual snackbar -->
  <div id="snackbar">{{ MSG }}</div>
</form> 


{% if MSG is defined %}
  <!-- Code only appears if MSG exists -->
  <script type="text/text/javascript">
    // Get the snackbar DIV
     var x = document.getElementById("snackbar");

    // Add the "show" class to DIV
     x.className = "show";

    // After 3 seconds, remove the show class from DIV
     setTimeout(function(){ x.className = x.className.replace("show", ""); }, 5000);
  </script>
{% endif %}

Django, in HTML template i used jinja2 in id = snackbar but when i click on the button the pop is just showing but no {{MSG}} in it, here is the url, views for contact.html:

urls

url(r'^contact', TemplateView.as_view(template_name= 'contact.html')),
url(r'^insertenquiry', insertenquiry, name='insertenquiry'),

views

def insertenquiry(request):
    if request.method == 'POST':
        fn = request.POST['firstname']
        ln = request.POST['lastname']
        emailid = request.POST['email']
        say = request.POST['saysomething']
        obj = Enquiry(fname=fn, lname=ln, email=emailid, saysomething=say)
        obj.save()
    msg = "sent success"
    return render(request,"contact.html",{'MSG':msg})

forms

from django import forms
from django.core import validators


class Enquiry(forms.Form):
    firstname = forms.CharField(max_length=100)
    lastname = forms.CharField(max_length=100)
    email = forms.EmailField(max_length=100)
    saysomething = forms.CharField(max_length=500)

models

from __future__ import unicode_literals
from django.db import models

# Create your models here.

class Enquiry(models.Model):
    fname = models.CharField(max_length= 100,unique=True)
    lname = models.CharField(max_length= 100)
    email = models.EmailField(max_length=100,unique=True)
    saysomething = models.CharField(max_length=500)

template: div tags are removed just for now.

<form method="POST" action="/insertenquiry/">{% csrf_token %}
<!-- <label for="fname">First Name</label> -->
<input type="text" name="firstname" class="form-control" placeholder="Your firstname" required>
<!-- <label for="lname">Last Name</label> -->
<input type="text" name="lastname" class="form-control" placeholder="Your lastname" required>
<!-- <label for="email">Email</label> -->
<input type="text" name="email" class="form-control" placeholder="Your email address" required>
<!-- <label for="message">Message</label> -->
<textarea name="saysomething" cols="30" rows="10" class="form-control" placeholder="Say something about us" required></textarea>
<!-- Use a button to open the snackbar -->
<button onclick="myFunction()">SEND ENQUIRY</button>
<!-- The actual snackbar -->
<div id="snackbar">{{MSG}}</div>

javascript

    function myFunction() {
      // Get the snackbar DIV
         var x = document.getElementById("snackbar");

      // Add the "show" class to DIV
         x.className = "show";

      // After 3 seconds, remove the show class from DIV
         setTimeout(function(){ x.className = x.className.replace("show", ""); }, 
         5000);}