SMTP Tester Tool

Enter your SMTP server address, port number, select encryption type, provide authentication credentials if required, and click test. The tool connects to your server, verifies credentials, and displays detailed connection results including success status, error messages, and comprehensive debug logs to help diagnose any connectivity issues.

Port 587 with TLS encryption is recommended for modern email sending and is widely supported by email providers. Port 465 uses SSL encryption and is also secure. Port 25 is the traditional SMTP port but is often blocked by ISPs to prevent spam. The tool automatically suggests appropriate ports based on your selected encryption type.

Yes, enter a recipient email address in the optional test email field to send an actual test message through your SMTP server. This verifies not only connection and authentication but also confirms end-to-end email delivery capability. The test email includes clear identification that it was sent from the SMTP testing tool for easy verification.

TLS is the modern successor to SSL and provides more secure encryption for email transmission. Port 587 with TLS uses STARTTLS, which upgrades an unencrypted connection to encrypted, while port 465 with SSL establishes encryption from the start. Most modern email providers recommend TLS on port 587 for security and compatibility reasons.

Common causes include incorrect server address or port, wrong authentication credentials, firewall blocking the connection, incorrect encryption settings, expired SSL certificates, or ISP blocking certain ports. The tool provides detailed debug logs showing exactly where the connection fails, helping you identify whether the issue is authentication, network connectivity, or configuration errors.

Most SMTP servers require authentication with username and password to prevent unauthorized email sending. However, some internal or local development servers may allow unauthenticated connections. If your server requires authentication, you must provide valid credentials. The tool indicates whether authentication succeeded or failed during the connection test.

Yes, use smtp.gmail.com as the server, port 587 with TLS encryption, your Gmail address as username, and an app-specific password (not your regular Gmail password) for authentication. Gmail requires app passwords for third-party applications when two-factor authentication is enabled. The tool can verify these settings work correctly before implementing them in your applications.

Debug logs show the complete SMTP conversation including connection establishment, server responses, authentication attempts, encryption negotiation, and any error messages. Sensitive information like passwords is automatically hidden for security. Logs help diagnose specific issues such as authentication failures, SSL certificate problems, or protocol mismatches with detailed technical information.

Test your SMTP plugin settings before configuring them in WordPress. Verify that server address, port, encryption type, and credentials work correctly using this tool. If the test succeeds here but WordPress emails still fail, the issue likely lies in WordPress configuration or plugin settings rather than SMTP connectivity, helping narrow down troubleshooting efforts significantly.

Yes, test results can be copied to your clipboard or downloaded as a text file for documentation and reference. Downloaded results include your configuration settings, test timestamp, connection status, and complete debug logs. This is useful for sharing troubleshooting information with technical support teams or maintaining records of server configurations for compliance purposes.

Passwords are transmitted securely and used only for immediate connection testing without being stored. However, consider using app-specific passwords or dedicated SMTP credentials rather than main account passwords for added security. For production systems, create separate email accounts or API credentials specifically for application email sending rather than using personal email credentials.

The tool works with all standard SMTP providers including Gmail, Outlook, Yahoo Mail, SendGrid, Mailgun, Amazon SES, Postmark, SparkPost, SMTP2GO, and any custom SMTP server following standard protocols. It supports both commercial email services and self-hosted mail servers running Postfix, Exim, or other SMTP server software with standard configurations.

Connection success means the server accepted your credentials and established communication. Email sending failures after successful connection often indicate issues with sender address validation, recipient address problems, message content triggering spam filters, daily sending limits reached, or insufficient permissions on the authenticated account. Check error messages for specific sending failure reasons.