SMTP Checker

Test SMTP server connections and verify email credentials with this free online tool

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About This Tool

The SMTP Checker is a comprehensive tool that allows you to test SMTP server connections, verify authentication credentials, and diagnose email sending issues. Simply enter your SMTP server details (host, port, username, password) and test emails to validate your configuration. The tool performs real SMTP connection tests and provides detailed feedback about authentication success, server response, and potential issues. Perfect for developers, system administrators, and anyone troubleshooting email delivery problems.

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How to Use

Enter your SMTP server hostname or IP address
Specify the port (common ports: 25, 465,
Provide authentication credentials (username and password)
Enter 'From' and 'To' email addresses for testing
Click 'Test SMTP Connection' to validate your configuration
View detailed results including connection status and authentication verification

Frequently Asked Questions

Find Quick Answers

What is SMTP and why do I need to test it?

SMTP (Simple Mail Transfer Protocol) is the standard protocol for sending emails. Testing SMTP connections helps verify that your email server is properly configured and can send emails successfully.

What information do I need to test my SMTP server?

You need your SMTP server hostname/address, port number, authentication credentials (username/password), and test email addresses for 'From' and 'To' fields.

Is my email password stored or logged when using this tool?

No, passwords are processed securely during the test session only and are not stored, logged, or persisted in any way.

What do the different SMTP ports mean?

Port 25 is for unencrypted SMTP, 465 is for SMTPS (SSL), and 587 is for SMTP with STARTTLS encryption. Most modern email services use ports 465 or 587 for secure connections.

Why is my SMTP test failing?

Common reasons include incorrect server details, wrong port, invalid credentials, firewall blocking the connection, or the SMTP server requiring specific security settings like TLS/SSL.

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