Bài 26: Email Configuration & Sending

Email Configuration

Django Email System cho phép gửi emails từ application với nhiều backends.

# settings.py - Basic email configuration # Email backend (how to send emails)EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend' # SMTP server settingsEMAIL_HOST = 'smtp.gmail.com'       # SMTP serverEMAIL_PORT = 587                    # TLS port (or 465 for SSL)EMAIL_USE_TLS = True                # Use TLS encryptionEMAIL_USE_SSL = False               # Use SSL encryption (alternative to TLS)EMAIL_HOST_USER = 'your@gmail.com'  # SMTP usernameEMAIL_HOST_PASSWORD = 'your-password'  # SMTP password # Default senderDEFAULT_FROM_EMAIL = 'noreply@example.com'SERVER_EMAIL = 'server@example.com'  # For error emails # Benefits:# - Transactional emails (registration, password reset)# - Notifications (new comment, message)# - Marketing emails# - Error reports

Email Backends

Available Backends

# settings.py # 1. SMTP Backend (Production)EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'# Sends real emails via SMTP server # 2. Console Backend (Development)EMAIL_BACKEND = 'django.core.mail.backends.console.EmailBackend'# Prints emails to console (no actual sending) # 3. File Backend (Testing)EMAIL_BACKEND = 'django.core.mail.backends.filebased.EmailBackend'EMAIL_FILE_PATH = BASE_DIR / 'sent_emails'# Saves emails to files # 4. In-Memory Backend (Testing)EMAIL_BACKEND = 'django.core.mail.backends.locmem.EmailBackend'# Stores emails in memory (for unit tests) # 5. Dummy Backend (Disable emails)EMAIL_BACKEND = 'django.core.mail.backends.dummy.EmailBackend'# Does nothing (discards emails) # Development vs Production:if DEBUG:    EMAIL_BACKEND = 'django.core.mail.backends.console.EmailBackend'else:    EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'

SMTP Configuration

Gmail SMTP

# settings.pyEMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'EMAIL_HOST = 'smtp.gmail.com'EMAIL_PORT = 587EMAIL_USE_TLS = TrueEMAIL_HOST_USER = 'your-email@gmail.com'EMAIL_HOST_PASSWORD = 'your-app-password'  # Use App Password, not regular passwordDEFAULT_FROM_EMAIL = 'Your Name <your-email@gmail.com>' # Gmail App Password:# 1. Enable 2-factor authentication# 2. Go to: https://myaccount.google.com/apppasswords# 3. Generate app password# 4. Use that password instead of your regular password # Note: Gmail has sending limits:# - Free: 500 emails/day# - Google Workspace: 2000 emails/day

Other SMTP Providers

# Outlook/HotmailEMAIL_HOST = 'smtp-mail.outlook.com'EMAIL_PORT = 587EMAIL_USE_TLS = True # YahooEMAIL_HOST = 'smtp.mail.yahoo.com'EMAIL_PORT = 465EMAIL_USE_SSL = True # SendGridEMAIL_HOST = 'smtp.sendgrid.net'EMAIL_PORT = 587EMAIL_USE_TLS = TrueEMAIL_HOST_USER = 'apikey'EMAIL_HOST_PASSWORD = 'your-sendgrid-api-key' # MailgunEMAIL_HOST = 'smtp.mailgun.org'EMAIL_PORT = 587EMAIL_USE_TLS = TrueEMAIL_HOST_USER = 'postmaster@your-domain.com'EMAIL_HOST_PASSWORD = 'your-mailgun-password' # AWS SESEMAIL_BACKEND = 'django_ses.SESBackend'AWS_ACCESS_KEY_ID = 'your-key'AWS_SECRET_ACCESS_KEY = 'your-secret'AWS_SES_REGION_NAME = 'us-east-1'AWS_SES_REGION_ENDPOINT = 'email.us-east-1.amazonaws.com'

Environment Variables (Best Practice)

# settings.pyimport os EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'EMAIL_HOST = os.environ.get('EMAIL_HOST', 'smtp.gmail.com')EMAIL_PORT = int(os.environ.get('EMAIL_PORT', 587))EMAIL_USE_TLS = os.environ.get('EMAIL_USE_TLS', 'True') == 'True'EMAIL_HOST_USER = os.environ.get('EMAIL_HOST_USER')EMAIL_HOST_PASSWORD = os.environ.get('EMAIL_HOST_PASSWORD')DEFAULT_FROM_EMAIL = os.environ.get('DEFAULT_FROM_EMAIL', 'noreply@example.com') # .env file:EMAIL_HOST=smtp.gmail.comEMAIL_PORT=587EMAIL_USE_TLS=TrueEMAIL_HOST_USER=your-email@gmail.comEMAIL_HOST_PASSWORD=your-app-passwordDEFAULT_FROM_EMAIL=Your Name <your-email@gmail.com> # Load with python-decouple:# pip install python-decouplefrom decouple import config EMAIL_HOST = config('EMAIL_HOST')EMAIL_HOST_USER = config('EMAIL_HOST_USER')EMAIL_HOST_PASSWORD = config('EMAIL_HOST_PASSWORD')

send_mail() Function

Basic send_mail()

from django.core.mail import send_mail # Simple emailsend_mail(    subject='Welcome to Our Site',    message='Thank you for registering!',    from_email='noreply@example.com',    recipient_list=['user@example.com'],    fail_silently=False,  # Raise exception on error) # Multiple recipientssend_mail(    subject='Newsletter',    message='Check out our latest news!',    from_email='newsletter@example.com',    recipient_list=[        'user1@example.com',        'user2@example.com',        'user3@example.com',    ],) # With default from_email (from settings)send_mail(    subject='Hello',    message='This is a test email.',    from_email=None,  # Uses DEFAULT_FROM_EMAIL    recipient_list=['user@example.com'],) # Return value: number of successfully sent emailsnum_sent = send_mail(    subject='Test',    message='Test message',    from_email='test@example.com',    recipient_list=['user@example.com'],)print(f'Sent {num_sent} emails')

send_mail() in Views

from django.shortcuts import render, redirectfrom django.contrib import messagesfrom django.core.mail import send_mailfrom django.conf import settings def contact_view(request):    if request.method == 'POST':        name = request.POST.get('name')        email = request.POST.get('email')        message = request.POST.get('message')                # Send email        try:            send_mail(                subject=f'Contact Form: {name}',                message=f'From: {name} <{email}>\n\n{message}',                from_email=settings.DEFAULT_FROM_EMAIL,                recipient_list=['admin@example.com'],                fail_silently=False,            )            messages.success(request, 'Your message has been sent!')            return redirect('contact')        except Exception as e:            messages.error(request, 'Failed to send message. Please try again.')        return render(request, 'contact.html')

send_mass_mail()

from django.core.mail import send_mass_mail # Send multiple emails at once (more efficient)message1 = (    'Subject 1',    'Message 1',    'from@example.com',    ['user1@example.com'])message2 = (    'Subject 2',    'Message 2',    'from@example.com',    ['user2@example.com'])message3 = (    'Subject 3',    'Message 3',    'from@example.com',    ['user3@example.com']) send_mass_mail(    (message1, message2, message3),    fail_silently=False) # Example: Newsletter to all usersusers = User.objects.filter(newsletter_subscribed=True)messages = [    (        'Weekly Newsletter',        f'Hello {user.first_name},\n\nHere are this week\'s updates...',        'newsletter@example.com',        [user.email]    )    for user in users]send_mass_mail(messages)

EmailMessage Class

Basic EmailMessage

from django.core.mail import EmailMessage # More control than send_mail()email = EmailMessage(    subject='Hello',    body='This is the email body.',    from_email='from@example.com',    to=['to1@example.com', 'to2@example.com'],    cc=['cc@example.com'],    bcc=['bcc@example.com'],    reply_to=['reply@example.com'],    headers={'Message-ID': 'foo'},) # Sendemail.send() # Or send multipleemail1 = EmailMessage(...)email2 = EmailMessage(...) # Open connection once, send multiplefrom django.core.mail import get_connection connection = get_connection()connection.open() email1.connection = connectionemail2.connection = connection email1.send()email2.send() connection.close()

EmailMessage with Attachments

from django.core.mail import EmailMessagefrom django.conf import settingsimport os # Attach file from pathemail = EmailMessage(    subject='Document Attached',    body='Please find the attached document.',    from_email='from@example.com',    to=['to@example.com'],)email.attach_file('/path/to/file.pdf')email.send() # Attach file from contentemail = EmailMessage(    subject='Report',    body='Please find the report attached.',    from_email='from@example.com',    to=['to@example.com'],)email.attach(    filename='report.txt',    content='This is the report content.',    mimetype='text/plain')email.send() # Attach multiple filesemail = EmailMessage(    subject='Files Attached',    body='Multiple files attached.',    from_email='from@example.com',    to=['to@example.com'],)email.attach_file('/path/to/file1.pdf')email.attach_file('/path/to/file2.docx')email.attach('data.csv', 'column1,column2\nvalue1,value2', 'text/csv')email.send() # Attach from FileFielddef send_document(request, document_id):    document = Document.objects.get(id=document_id)        email = EmailMessage(        subject=f'Document: {document.title}',        body='Your requested document is attached.',        from_email='documents@example.com',        to=[request.user.email],    )    email.attach_file(document.file.path)    email.send()        return redirect('documents')

HTML Emails

Simple HTML Email

from django.core.mail import send_mail # send_mail with HTMLsend_mail(    subject='Welcome!',    message='Plain text version',  # Fallback    from_email='from@example.com',    recipient_list=['to@example.com'],    html_message='<h1>Welcome!</h1><p>Thank you for joining!</p>',) # EmailMessage with HTMLfrom django.core.mail import EmailMultiAlternatives email = EmailMultiAlternatives(    subject='Welcome!',    body='Plain text version',  # Fallback    from_email='from@example.com',    to=['to@example.com'],)html_content = '<h1>Welcome!</h1><p>Thank you for joining!</p>'email.attach_alternative(html_content, "text/html")email.send()

HTML Email with Template

from django.core.mail import EmailMultiAlternativesfrom django.template.loader import render_to_stringfrom django.utils.html import strip_tags def send_welcome_email(user):    # Render HTML template    html_content = render_to_string('emails/welcome.html', {        'user': user,        'site_name': 'My Site',    })        # Create plain text version    text_content = strip_tags(html_content)        # Send email    email = EmailMultiAlternatives(        subject='Welcome to My Site!',        body=text_content,        from_email='noreply@example.com',        to=[user.email],    )    email.attach_alternative(html_content, "text/html")    email.send() # Template: emails/welcome.html<!DOCTYPE html><html><head>    <style>        body { font-family: Arial, sans-serif; }        .header { background: #007bff; color: white; padding: 20px; }        .content { padding: 20px; }        .button {             background: #007bff;             color: white;             padding: 10px 20px;             text-decoration: none;            display: inline-block;            border-radius: 5px;        }    </style></head><body>    <div class="header">        <h1>Welcome to {{ site_name }}!</h1>    </div>    <div class="content">        <p>Hello {{ user.first_name }},</p>        <p>Thank you for joining our community!</p>        <p>            <a href="https://example.com/profile/" class="button">                Complete Your Profile            </a>        </p>    </div></body></html>

Email with Inline Images

from django.core.mail import EmailMultiAlternativesfrom django.template.loader import render_to_stringfrom email.mime.image import MIMEImage def send_email_with_logo(user):    email = EmailMultiAlternatives(        subject='Welcome!',        body='Plain text version',        from_email='from@example.com',        to=[user.email],    )        # HTML content with image reference    html_content = '''    <html>        <body>            <img src="cid:logo" alt="Logo">            <h1>Welcome!</h1>        </body>    </html>    '''    email.attach_alternative(html_content, "text/html")        # Attach image    with open('path/to/logo.png', 'rb') as f:        logo = MIMEImage(f.read())        logo.add_header('Content-ID', '<logo>')        email.attach(logo)        email.send()

Email Templates

Reusable Email Function

# utils/email.pyfrom django.core.mail import EmailMultiAlternativesfrom django.template.loader import render_to_stringfrom django.utils.html import strip_tagsfrom django.conf import settings def send_template_email(    subject,    template_name,    context,    recipient_list,    from_email=None):    """Send email using template"""        # Render HTML    html_content = render_to_string(f'emails/{template_name}.html', context)    text_content = strip_tags(html_content)        # Create email    email = EmailMultiAlternatives(        subject=subject,        body=text_content,        from_email=from_email or settings.DEFAULT_FROM_EMAIL,        to=recipient_list,    )    email.attach_alternative(html_content, "text/html")        # Send    return email.send() # Usage:send_template_email(    subject='Welcome!',    template_name='welcome',    context={'user': user, 'site_name': 'My Site'},    recipient_list=[user.email],)

Common Email Templates

# Registration confirmationdef send_registration_email(user, activation_link):    send_template_email(        subject='Confirm Your Registration',        template_name='registration_confirm',        context={            'user': user,            'activation_link': activation_link,        },        recipient_list=[user.email],    ) # Password resetdef send_password_reset_email(user, reset_link):    send_template_email(        subject='Password Reset Request',        template_name='password_reset',        context={            'user': user,            'reset_link': reset_link,        },        recipient_list=[user.email],    ) # Order confirmationdef send_order_confirmation_email(order):    send_template_email(        subject=f'Order Confirmation #{order.id}',        template_name='order_confirmation',        context={            'order': order,            'customer': order.customer,            'items': order.items.all(),        },        recipient_list=[order.customer.email],    ) # Comment notificationdef send_comment_notification(comment):    send_template_email(        subject=f'New comment on: {comment.post.title}',        template_name='comment_notification',        context={            'comment': comment,            'post': comment.post,            'author': comment.post.author,        },        recipient_list=[comment.post.author.email],    )

Contact Form Implementation

Complete Contact Form

# forms.pyfrom django import forms class ContactForm(forms.Form):    name = forms.CharField(max_length=100)    email = forms.EmailField()    subject = forms.CharField(max_length=200)    message = forms.CharField(widget=forms.Textarea)        def send_email(self):        # Send email        from django.core.mail import send_mail        from django.conf import settings                send_mail(            subject=f"Contact: {self.cleaned_data['subject']}",            message=f"From: {self.cleaned_data['name']} <{self.cleaned_data['email']}>\n\n"                    f"{self.cleaned_data['message']}",            from_email=settings.DEFAULT_FROM_EMAIL,            recipient_list=['admin@example.com'],            fail_silently=False,        ) # views.pyfrom django.shortcuts import render, redirectfrom django.contrib import messagesfrom .forms import ContactForm def contact_view(request):    if request.method == 'POST':        form = ContactForm(request.POST)        if form.is_valid():            try:                form.send_email()                messages.success(request, 'Your message has been sent successfully!')                return redirect('contact')            except Exception as e:                messages.error(request, 'Failed to send message. Please try again later.')    else:        form = ContactForm()        return render(request, 'contact.html', {'form': form}) # Template: contact.html<h2>Contact Us</h2> {% if messages %}    {% for message in messages %}        <div class="alert alert-{{ message.tags }}">            {{ message }}        </div>    {% endfor %}{% endif %} <form method="post">    {% csrf_token %}    {{ form.as_p }}    <button type="submit">Send Message</button></form>

Bài Tập

Bài 1: Registration Email System

Task: Implement registration with email confirmation:

# Requirements:# 1. User registration form# 2. Send confirmation email with activation link# 3. Email template (HTML + plain text)# 4. Activation view to confirm email# 5. Set user.is_active = False until confirmed# 6. Token-based activation (expires in 24h)# 7. Resend confirmation email option# 8. Success/error messages# 9. Redirect after activation# 10. Test with console backend

Bài 2: Password Reset Flow

Task: Complete password reset with email:

# Requirements:# 1. Forgot password form (email input)# 2. Generate reset token# 3. Send password reset email# 4. Reset link expires in 1 hour# 5. Reset password form (new password)# 6. Validate token and expiration# 7. Update password# 8. Send confirmation email after reset# 9. Handle invalid/expired tokens# 10. Use Django's built-in password reset views

Bài 3: Notification System

Task: Build email notification system:

# Requirements:# 1. Comment notification to post author# 2. New follower notification# 3. Like notification# 4. Weekly digest email (summary of activity)# 5. User preference for email notifications# 6. HTML email templates for each type# 7. Batch sending for digest# 8. Unsubscribe link in emails# 9. Track email open/click (optional)# 10. Queue emails for async sending (Celery)

Bài 4: Complete Email System

Task: Full-featured email system:

# Requirements:# 1. Multiple email templates (welcome, notification, etc.)# 2. Base email template (header, footer, styling)# 3. Template inheritance for emails# 4. Attachment support# 5. Inline images (logo, icons)# 6. Email queue/retry mechanism# 7. Email logs (sent/failed)# 8. Admin interface for email management# 9. Email preview in browser# 10. A/B testing for email templates# 11. Responsive email design# 12. Test suite for emails

Tài Liệu Tham Khảo

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Project 10: Notification Service

Django Email Configuration & Sending