OTP Email Service

Send OTP codes by email and verify user email addresses.

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Features

Feature	Description
Send OTP	Generate and send verification code via email
Verify OTP	Validate user email verification code
SMTP Support	Works with Gmail, Outlook, custom SMTP
Django Ready	Easy integration with Django projects
Secure	Expiration time and retry support
Reusable	Can be used for login, signup, password reset

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SMTP Connection Test

Test SMTP with Telnet

telnet EMAIL_HOST EMAIL_PORT

Example:

telnet smtp.gmail.com 587

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Test Email Sending in Django

Open Django shell:

python manage.py shell

Run:

from django.core.mail import send_mail
from django.conf import settings

send_mail(
    subject='Test Subject',
    message='This is a test email.',
    from_email=settings.EMAIL_HOST_USER,
    recipient_list=['example@gmail.com'],
    fail_silently=False,
)

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Environment Variables

EMAIL_BACKEND=django.core.mail.backends.smtp.EmailBackend

EMAIL_HOST=smtp.gmail.com
EMAIL_PORT=587

EMAIL_HOST_USER=your-email@gmail.com
EMAIL_HOST_PASSWORD=your-password

EMAIL_USE_TLS=True
EMAIL_USE_SSL=False

DEFAULT_FROM_EMAIL=your-email@gmail.com

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OTP Authentication Flow

Step	Action
1	User enters email
2	System generates OTP code
3	OTP sent via email
4	User enters received code
5	System verifies OTP
6	User authenticated / verified

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Suggested Database Tables

OTP Codes Table

Column	Type	Description
id	UUID / Integer	Primary key
email	String	User email
code	String	OTP code
is_used	Boolean	Verification status
expired_at	DateTime	Expiration time
created_at	DateTime	Created timestamp

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Login Attempts Table

Column	Type	Description
id	UUID / Integer	Primary key
email	String	User email
ip_address	String	Client IP
status	String	Success / Failed
created_at	DateTime	Login timestamp

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Security Recommendations

• OTP expiration: 2–5 minutes
• Limit resend attempts
• Limit verification attempts
• Store hashed OTP codes
• Add rate limiting
• Log suspicious activity

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Example Use Cases

• Email verification
• Password reset
• Two-factor authentication (2FA)
• Passwordless login
• Signup verification