SMTPBOX DOCS
Connect. Capture.
Test your email.
Connect your SMTP mailer, inspect test emails, automate email tests and troubleshoot SMTPBox with these developer guides.
SMTPBox quickstart: capture your first test email
Create an inbox, generate SMTP credentials and capture your first development email with SMTPBox.
Read documentation →SMTPBox plans, limits and email retention
Compare Free and Unlimited allowances, team access, API rate limits and test-message retention.
Read documentation →SMTP server settings: ports, TLS and credentials
Connect to smtp.smtpbox.dev using STARTTLS on 587 or 2525, or implicit TLS on 465, with inbox credentials.
Read documentation →SMTP configuration examples for PHP, Python and Symfony
Connect popular mail libraries to SMTPBox with configuration examples and links to Laravel and Nodemailer setup guides.
Read documentation →Inspect test emails, headers, links and attachments
Use the SMTPBox message inspector to check HTML, plain text, raw MIME, recipients, links and attachments.
Read documentation →Catch-all inbound email testing with SMTPBox
Use optional receiving domains to capture replies and test inbound email workflows in a development inbox.
Read documentation →SMTPBox API keys and authentication
Create read-only or read/write API keys and authenticate REST requests with a Bearer token.
Read documentation →SMTPBox REST API reference
API endpoints for inboxes, message search, waiting for email, message bodies, headers, attachments and usage.
Read documentation →Automated email testing with the SMTPBox API
Trigger an application email, wait for a matching recipient and subject, and assert the captured message in automated tests.
Read documentation →SMTPBox email webhooks and signature verification
Receive message.received events, verify the SMTPBox-Signature header and handle retries safely.
Read documentation →SMTP errors: fix 535 authentication and TLS failures
Diagnose SMTP 535, 530, 421, 451, 452 and 550 responses, connection timeouts and TLS configuration errors.
Read documentation →SMTPBox API errors and HTTP status codes
Understand authentication failures, permissions, validation errors, rate limits and email wait timeouts.
Read documentation →Troubleshoot missing development emails
Check application queues, SMTP credentials, TLS settings, workspace usage and retention when test emails do not appear.
Read documentation →Configure Laravel email testing with SMTPBox
Configure Laravel SMTP settings, send a test message and diagnose cached configuration and queue-worker issues.
Read documentation →Configure Nodemailer SMTP email testing
Send a Node.js test email with Nodemailer, require STARTTLS and troubleshoot SMTP authentication and timeouts.
Read documentation →