Do I need an email API for sending OTP codes?

Not necessarily.

If you’re sending OTPs by email, you need a way to deliver email, but that doesn’t always mean a separate “email API” product.

Your options

1. Use an email service/API

   • Examples: SendGrid, Mailgun, Amazon SES, Postmark, Resend
   • Best for: reliability, deliverability, scaling, tracking, avoiding spam issues
   • Usually the recommended choice for apps

2. Use your own SMTP server

   • You can send emails directly via SMTP from your backend
   • Works for small/internal systems
   • Downsides: harder deliverability, more maintenance, more likely to hit spam filters

3. Use transactional email through your app framework

   • Many frameworks/libraries still rely on an underlying SMTP server or email API
   • So this is usually not truly “without an email service”

For OTPs specifically

You should use a transactional email provider if possible, because OTPs are:

• time-sensitive
• high-priority
• should arrive quickly
• often need good deliverability

Bottom line

• No, you don’t strictly need a dedicated email API
• Yes, you do need some email delivery method
• For production OTPs, an email API/service is strongly recommended

If you want, I can recommend the easiest setup for your stack (Node, Python, PHP, etc.).