Analyze SMTP Logs for Email Encryption Issues

For email security administrators and developers who need to audit SMTP logs for encryption compliance. Paste your logs and instantly see which sessions used TLS, which TLS versions were negotiated, and which messages were sent in plaintext — so you can flag risky transmissions before they become a breach.

Open the Tool

Why use Email Encryption Analyzer?

Instantly detect STARTTLS and TLS handshake events in raw SMTP logs

Identify plaintext (unencrypted) email sessions that expose message content

Report negotiated TLS versions to spot outdated or weak protocols

Map encryption status per connection and per message transaction

Runs entirely in your browser — no logs are uploaded or stored

How it works

  1. Copy the relevant lines from your SMTP server log (Postfix, Exim, Sendmail, Exchange, etc.).
  2. Paste the log text into the SMTP Server Logs input box.
  3. Click 'Analyze Encryption' to generate the report.
  4. Review the output for encrypted sessions, TLS versions, and flagged plaintext transmissions.

FAQ

What log formats are supported?

The analyzer works with common SMTP server log lines that include connection events, STARTTLS commands, TLS handshake results, MAIL FROM, RCPT TO, DATA, and status codes. Postfix, Exim, and similar text-based logs are supported.

How does it determine if a session is encrypted?

It looks for STARTTLS commands followed by successful TLS handshake lines (for example, 'TLSv1.2 handshake successful'). Sessions with mail transactions but no TLS handshake are flagged as plaintext.

Are my logs sent to a server?

No. All analysis happens locally in your browser. Your SMTP logs never leave your device and are not stored anywhere.

Can it detect weak TLS versions?

Yes. The report lists the TLS versions found in handshake lines, so you can quickly see if deprecated versions like TLSv1.0 or TLSv1.1 are still in use.

Is this a replacement for a full email security audit?

No. It is a fast triage tool to highlight encryption gaps in SMTP logs. Use it alongside your broader compliance and security review processes.