Email APIs provide services for sending transactional and marketing emails, validating email addresses, detecting disposable email domains, and managing email delivery for web applications.

Which email sending API has a free tier?

SendGrid offers 100 free emails per day. Mailgun provides 5,000 free emails per month for 3 months. Resend and Brevo also offer generous free tiers for transactional email sending.

How do I send a transactional email with an API?

Authenticate with your API key, then POST a JSON payload containing the recipient, subject, and HTML body to the provider's send endpoint. Most providers also offer official SDKs for popular languages.

Email APIs

Email services and validation

17 APIs in this category

Showing 17 of 17 APIs

Abstract Email Validation

Validate email addresses for deliverability, syntax, and spam risk detection

Auth: apiKey HTTPS CORS: Yes

apilayer mailboxlayer

Real-time email address validation and verification service

Auth: apiKey HTTPS CORS: Unknown

Cloudmersive Validate

Validate email addresses, phone numbers, VAT numbers, and domain names

Auth: apiKey HTTPS CORS: Yes

Disify

Detect disposable, temporary, and invalid email addresses instantly

Auth: No HTTPS CORS: Yes

DropMail

GraphQL API for generating and managing temporary email inboxes

Auth: No HTTPS CORS: Unknown

EVA

Simple and fast email validation API

Auth: No HTTPS CORS: Yes

Guerrilla Mail

API for creating disposable and temporary email addresses

Auth: No HTTPS CORS: Unknown

ImprovMX

API for custom email forwarding and routing

Auth: apiKey HTTPS CORS: Unknown

Kickbox

Free and reliable email verification API for real-time validation

Auth: No HTTPS CORS: Yes

mail.gw

Temporary email API for creating disposable inboxes (10-minute mail)

Auth: No HTTPS CORS: Yes

mail.tm

API for generating temporary and anonymous email addresses

Auth: No HTTPS CORS: Yes

MailboxValidator

Validate and verify email addresses to improve deliverability

Auth: apiKey HTTPS CORS: Unknown

MailCheck.ai

Detect and block disposable or fake email addresses during signup

Auth: No HTTPS CORS: Unknown

Mailtrap

Safe email testing tool for development and staging environments

Auth: apiKey HTTPS CORS: Unknown

Sendgrid

Cloud-based SMTP and transactional email sending API

Auth: apiKey HTTPS CORS: Unknown

Sendinblue

Marketing and transactional email/SMS API with advanced analytics

Auth: apiKey HTTPS CORS: Unknown

Verifier

API for verifying whether an email address is active and valid

Auth: apiKey HTTPS CORS: Yes

API	Description	Auth	HTTPS	CORS
Abstract Email Validation	Validate email addresses for deliverability, syntax, and spam risk detection	apiKey	✓	✓
apilayer mailboxlayer	Real-time email address validation and verification service	apiKey	✓	?
Cloudmersive Validate	Validate email addresses, phone numbers, VAT numbers, and domain names	apiKey	✓	✓
Disify	Detect disposable, temporary, and invalid email addresses instantly	No	✓	✓
DropMail	GraphQL API for generating and managing temporary email inboxes	No	✓	?
EVA	Simple and fast email validation API	No	✓	✓
Guerrilla Mail	API for creating disposable and temporary email addresses	No	✓	?
ImprovMX	API for custom email forwarding and routing	apiKey	✓	?
Kickbox	Free and reliable email verification API for real-time validation	No	✓	✓
mail.gw	Temporary email API for creating disposable inboxes (10-minute mail)	No	✓	✓
mail.tm	API for generating temporary and anonymous email addresses	No	✓	✓
MailboxValidator	Validate and verify email addresses to improve deliverability	apiKey	✓	?
MailCheck.ai	Detect and block disposable or fake email addresses during signup	No	✓	?
Mailtrap	Safe email testing tool for development and staging environments	apiKey	✓	?
Sendgrid	Cloud-based SMTP and transactional email sending API	apiKey	✓	?
Sendinblue	Marketing and transactional email/SMS API with advanced analytics	apiKey	✓	?
Verifier	API for verifying whether an email address is active and valid	apiKey	✓	✓

Best Email APIs for Developers

An email API allows developers to send transactional emails, validate addresses, detect disposable domains, and manage delivery infrastructure without running their own mail servers. These APIs are critical for password resets, order confirmations, and notification systems.

CodeHelper's curated email API collection includes APIs covering transactional sending, bulk campaigns, address verification, and temporary email detection.

What to look for in an email API

Deliverability: Choose providers with strong sender reputation and built-in SPF/DKIM support for high inbox placement rates.
Webhook events: Delivery, open, and click webhooks let you track email engagement and handle bounces programmatically.
Template support: Dynamic templates with variable substitution simplify sending personalized emails at scale.

How to use this API directory

Browse the curated list of APIs below.
Click any API to visit its documentation.
Check the Auth column to understand what credentials you need.

Whether you are building a notification system or an email validation service, this free curated API directory saves you hours of research.

Email APIs

Abstract Email Validation

apilayer mailboxlayer

Cloudmersive Validate

Disify

DropMail

EVA

Guerrilla Mail

ImprovMX

Kickbox

mail.gw

mail.tm

MailboxValidator

MailCheck.ai

Mailtrap

Sendgrid

Sendinblue

Verifier

Best Email APIs for Developers

What to look for in an email API

How to use this API directory

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