What is an SMTP banner?

It is the initial text string returned by the mail server upon a successful connection, often containing the server software name and version.

Which port should I use?

Port 25 is standard but often blocked by ISPs to prevent spam. Port 587 is used for secure submission (STARTTLS), and 465 is used for implicit SSL/TLS.

Does this test authentication?

No, this tool simply verifies network connectivity and banner response at the TCP level. It does not attempt to log in or send an email.

SMTP Test

Test connectivity to a Mail Server (SMTP) on a specific port.

What is the SMTP Test?

The SMTP Test tool verifies connectivity to a Simple Mail Transfer Protocol (SMTP) server. It attempts a TCP connection and retrieves the server's greeting banner.

How to use it

Enter the SMTP server address (e.g., smtp.gmail.com).
Enter the port (usually 25, 465, or 587).
Click "Test Connection" to view the banner.

SMTP Test

Connection Results

What is the SMTP Test?

How to use it

Frequently Asked Questions