SMTP Server Configuration Tester

Verify connection parameters, active authentication ports, and handshake responses on mail servers.

SMTP Test Workspace

SMTP Server Credentials

Enter mail server relay settings to test handshakes and credentials

Handshake Status: Pass
Server Response: OK
⚙️ Server Target
  • Host: -
  • Port: -
🛠️ Diagnostics Details
  • Encryption: -
  • Response Banner: -
  • Relay Errors: -

Validate Mail Relay Settings

Why operations teams, outreach specialists, and systems admins test SMTP server ports

Connection Handshakes

Validates that the host is accessible and establishes a connection socket immediately.

Credential Audits

Tests active SMTP username and password authentication to prevent relay access denied codes.

Encryption Handshakes

Validates support for SSL and TLS layers on standard ports 465, 587, and 25.

Follow these simple steps to audit your mail server settings

Provide Server Host

Enter the SMTP server address (e.g. smtp.gmail.com or smtppro.zoho.com).

Configure Ports & SSL

Select the port number (e.g. 465, 587) and specify your preferred encryption standard.

Provide Credentials

Fill in the authentication email and password for the SMTP relay account.

Validate Relay

Click "Test SMTP Connection" to run handshake queries and isolate connection errors.

Frequently Asked Questions

Answers to common inquiries about SMTP relays ports and SSL/TLS negotiation settings

What is SMTP and why test it?
Simple Mail Transfer Protocol (SMTP) is the standard protocol for sending emails. Testing your SMTP configurations ensures your outbound servers are reachable, authenticated, and secure before sending outreach campaigns.
What port should I use for SMTP?
Use port 465 for secure SSL connections, port 587 for modern STARTTLS connections, or port 25 for standard unencrypted/internal relays. Modern systems prefer port 465 or 587.
Are my SMTP credentials secure?
Yes. Credentials entered are sent securely to the test API to establish a temporary socket connection and are never saved or stored. If the backend is offline, tests execute as a safe client-side simulation.