SMTP Test Tool

SMTP Server

Port

Username

Password

From Email

To Email

Security

Test Results

Testing...

How to Use the SMTP Test Tool

Follow these simple steps to verify your mail server configurations.

Enter SMTP Details

Provide your outgoing server address (host), port number, and login credentials (username and password).

Set Test Emails

Enter the sender's address in "From Email" and the recipient's address in "To Email" fields.

Run Connection Check

Click "Test SMTP Connection". The tool will initiate a handshake with your server and print debug logs.

About the SMTP Test Tool

The SMTP Test Tool is a vital utility for web developers, system administrators, and email marketers designed to verify outgoing email server configurations. Simple Mail Transfer Protocol (SMTP) is the internet standard protocol used to deliver email messages. Misconfigured ports, authentication issues, or incorrect server hostnames can lead to delivery failures, sending errors, or emails being flagged as spam.

Our tool makes it simple to run instant connectivity tests. By performing the full SMTP handshake in real-time, it lets you inspect communication records and troubleshoot issues. Since the check executes via a secure server-side script, your SMTP credentials are protected and never stored.

Common SMTP Ports and Security Types

Choosing the correct combination of port and encryption is crucial for establishing a secure connection to your mail server:

Port 587 (TLS / STARTTLS)

This is the standard modern port for email submission. It initiates an unencrypted connection first and then upgrades it to TLS security via the STARTTLS command.

Port 465 (SSL / SMTPS)

Historically used for secure SMTP. It establishes an implicit SSL connection immediately upon connecting to the server. Very common for services like Gmail.

Port 25 (Standard SMTP)

The original default port. However, it is widely blocked by residential internet service providers (ISPs) and cloud hosting networks to prevent outbound spam.

Port 2525 (Alternative)

An alternative submission port supported by many email service providers. It can be used if Port 587 or Port 465 are blocked by local firewalls.

Frequently Asked Questions

Find answers to common questions about SMTP testing

What is an SMTP server?

SMTP (Simple Mail Transfer Protocol) is the standard protocol for sending emails across the Internet. An SMTP server is a computer or service that handles sending, receiving, and relaying outgoing mail between email senders and receivers.

Why should I test my SMTP server?

Testing your SMTP server helps ensure that your email delivery system is working correctly. It can identify authentication issues, port blocking, or configuration problems that might prevent your emails from being delivered.

What are common SMTP ports?

The most common SMTP ports are: 25 - Default SMTP port (often blocked by ISPs), 587 - Default mail submission port (with TLS), 465 - SSL encrypted SMTP port, and 2525 - Alternative port when others are blocked.

Is my SMTP login information secure?

Yes, all SMTP tests are performed securely. Your credentials are never stored on our servers and are only used for the duration of the connection test.

What does 'Connection timed out' mean?

This error typically means that our tool couldn't establish a connection to your SMTP server. Possible causes include: The server address is incorrect, the server is not responding, the port is blocked by a firewall, or the server is not accessible from the Internet.