Demo mode — Results are simulated. The real SMTP probe backend is not yet connected.

What does your mail server actually say?

When email stops working, the useful question is what the mail server says to a client that connects to it. Smtpprobe answers that directly: enter a hostname, and the probe reads the greeting banner and reports back what it found.

Try the Probe See Pricing

How it works

The check an admin would do by hand with a terminal, for people who do not have a terminal.

Probe
220 mail.example.com ESMTP Postfix (Ubuntu)
250-SIZE 35882577
250-STARTTLS
250-AUTH PLAIN LOGIN
250-SMTPUTF8
250 DSN

What the probe tells you

Each result is a structured finding, not a blob of raw text. Read your server's configuration at a glance.

  • B

    SMTP banner

    The greeting the server sends when you connect — identifies the server software and hostname.

  • T

    STARTTLS detection

    Knows whether the server offers STARTTLS for upgrading a plain-text connection to encrypted.

  • A

    Auth mechanism listing

    Shows which authentication mechanisms the server advertises — PLAIN, LOGIN, CRAM-MD5, and others.

  • T

    Handshake timing

    Measures the round-trip time from connection open to receiving the first banner line.

Ready to probe your server?

No account needed. No data stored. Just a tool that answers when you ask it.

Open the Probe