The Devmailr Blog
Practical guides on testing email in automated tests and CI/CD pipelines — OTP codes, verification links, deliverability, and the tools that make it painless.
New to email testing? Start here.
Email Testing Best Practices for Developers
Ten practical rules for reliable email testing — isolated inboxes, waiting instead of sleeping, extracting codes, cleaning up, and asserting deliverability.
How to Test Auth0 Email Verification
Auth0 verifies email with a link (and optional passwordless codes). Here's how to catch and follow them in an automated test using a disposable inbox.
How to Test Clerk Email Verification Codes
Clerk sends a one-time email code on signup. Here's how to read that code in your tests with a disposable inbox — no manual steps, no flaky regexes.
Email Testing in Node.js with Jest
Test the emails your Node.js app sends — verification codes and reset links — from a Jest or Vitest suite, using a disposable inbox and a small async helper.
Email Testing in Postman: Wait for a Verification Email
Automate an email verification flow inside a Postman collection — create an inbox, trigger your app, then pull the code from the message with test scripts.
How to Test Email in PHP with PHPUnit
Test signup, OTP, and password-reset emails from PHPUnit — create a disposable inbox, wait for the message, and assert on the code or link, with Guzzle.
Email Testing in C# and .NET
Test the emails your .NET app sends from an xUnit suite — create a disposable inbox with HttpClient, wait for the email, and read the verification code.
A MailSlurp Alternative for Email Testing
Looking for a simpler, cheaper MailSlurp alternative for email testing? Here's how Devmailr compares on API, wait-for-email, code extraction, and price.
A Mailtrap Alternative for Receiving Test Email
Mailtrap captures the email your app sends; Devmailr receives real email at an address. Here's how the two differ and when to choose each.
A Mailosaur Alternative for Email and Test Automation
A simpler, lower-cost Mailosaur alternative for developers who mainly need to read verification emails in CI. Here's how Devmailr compares.
What Is a Disposable Email Address? A Developer’s Guide
What a disposable (temporary) email address is, how it works, when developers should use one, and how to spin one up over an API for testing.
How to Receive Email Programmatically with an API
Receiving inbound email used to mean running a mail server. Here’s how to receive and parse email over a simple REST API instead — with code.
Cypress Email Testing: Verify Signup and OTP Flows End-to-End
A complete Cypress example that signs a user up, waits for the verification email via a disposable inbox API, and submits the code — with reusable custom commands.
Selenium Email Testing: Automate Verification in Java and Python
How to test email-based signup and OTP flows with Selenium by reading the message from a disposable inbox API. Java and Python examples included.
How to Test Email in Python with pytest
Test signup, OTP, and password-reset emails from your pytest suite — create a disposable inbox, wait for the email, and assert on the code or link.
How to Test a Password Reset Flow End-to-End
The forgot-password flow is easy to break and rarely tested. Here’s how to test it end-to-end — request a reset, catch the email, follow the link, set a new password.
How to Test Magic Link (Passwordless) Login
Magic-link auth is hard to test because the link arrives by email. Here’s how to capture it from a disposable inbox and complete passwordless login in a test.
How to Test Email Signup and Account Verification
A step-by-step guide to testing the signup and email-verification flow end to end — covering both the verification code and the confirmation link.
Receive Email in Real Time Without Running a Webhook Server
CI runners and local scripts can’t host a webhook. Here’s how to stream inbound email over Server-Sent Events instead — no public URL required.
A Mailinator Alternative Built for Automated Testing
Looking for a Mailinator alternative with a real API, wait-for-email, and private inboxes? Here’s how Devmailr compares for automated test workflows.
The Best Disposable Email APIs for Testing (2026)
A developer's comparison of disposable and test-email APIs — Devmailr, MailSlurp, Mailosaur, Mailtrap, testmail, and Mailinator — by features, automation, and price.
How to Test SPF, DKIM, and DMARC in Your Email Pipeline
Catch broken email authentication before your users do. Send a real message to a disposable inbox and assert on the SPF, DKIM, and DMARC verdicts in CI.
Playwright Email Testing: Wait for a Verification Email and Extract the Code
A complete Playwright example that signs a user up, waits for the verification email via a disposable inbox API, extracts the code, and finishes the flow — no polling boilerplate.
How to Test OTP and 2FA Verification Codes in Automated Tests
Stop regexing email bodies. Here's how to pull one-time passcodes and verification codes out of test emails reliably — and wait for them — using a disposable inbox API.
How to Test Email in Your CI/CD Pipeline (Without a Real Inbox)
A practical guide to testing signup, OTP, and password-reset emails in CI — create a disposable inbox over an API, wait for the message, and assert on it. With copy-paste code.