Start/notes.ini Parameters/SMTPLogTLSSessions

SMTPLogTLSSessions

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Parameter: SMTPLogTLSSessions
Short description: Logs the negotiated TLS version and cipher suite for every inbound and outbound SMTP connection – useful for compliance and interop evidence.

Profile

Parameter
SMTPLogTLSSessions
Category
Logging / Debug
Component
Server
Available since
10.0
Supported versions
10.0, 11.0, 12.0, 14.0, 14.5, 14.5.1
GUI equivalent
notes.ini only (no GUI)
Possible values
0 = off • 1 = one line per connection

Description

With SMTPLogTLSSessions=1, the SMTP task writes one line per TLS-secured connection to the log, containing the TLS version (e.g. TLSv1.2 / TLSv1.3) and the negotiated cipher suite. Unlike SMTPDebug, this is lightweight logging – so it can be enabled permanently when you need compliance evidence for mail encryption or want to analyze interop issues with particular peers.

Example configuration

SMTPLogTLSSessions=1

Notes & pitfalls

  • Low performance impact – can stay enabled in production.
  • Takes effect after restart task smtp.
  • For deeper troubleshooting, additionally enable SMTPDebug=2.
  • Complementary to SSL_DEBUG.