Start/notes.ini Parameters/SMTPDebug

SMTPDebug

Parameter: SMTPDebug
Short description: Enables capturing of inbound SMTP protocol conversations that the Domino SMTP listener receives from other servers and clients. Four detail levels (1–4); additionally requires debug_outfile.

Profile

Parameter
SMTPDebug
Component
Server (SMTP listener)
Category
Mail / Router (debug)
Available since
9.0.x (per KB0032184)
Default
0 (disabled)
Values
0 (off), 1, 2, 3, 4 (increasingly verbose)
Additionally requires
debug_outfile=<path/file.txt> in notes.ini
Output destination
File from debug_outfile (not log.nsf)

Detail levels per KB0032184

Value
Meaning
0
Logging disabled (default)
1
Minimal listener logging
2
Info logging: sent/received data, byte counts, additional debug information — without transferred plain text
3
Verbose: additionally the plain text transferred via SMTP (commands and responses); no mail body
4
Maximum detail level

Description

Whereas SMTPClientDebug captures the outbound direction, SMTPDebug logs the inbound direction at the SMTP listener — i.e. everything that foreign systems send to Domino: TCP connection setup, EHLO/HELO, STARTTLS negotiation, AUTH, MAIL FROM, RCPT TO, DATA, response codes from the Domino server (250, 421, 550, 554, ...).
Per KB0032184, SMTPDebug does not write its output to log.nsf. Instead, debug_outfile=<path> must additionally be set in notes.ini — that is where a text file with the capture is created. Without debug_outfile, the output is lost.

Examples

Medium detail level in notes.ini:
SMTPDebug=2
debug_outfile=C:\\Domino\\Logs\\smtp_debug.txt
Verbose capture for diagnosing a specific issue:
SMTPDebug=3
debug_outfile=/local/notesdata/IBM_TECHNICAL_SUPPORT/smtp_debug.txt
Dynamically via the server console:
set config SMTPDebug=2
set config debug_outfile=C:\\Domino\\Logs\\smtp_debug.txt
tell smtp quit
load smtp
Deactivate — back to 0:
set config SMTPDebug=0
tell smtp quit
load smtp

Notes

  • debug_outfile mandatory – Without this second parameter, no SMTPDebug capture is persisted.
  • File can grow large – KB0032184 warns: only enable logging for the duration of reproduction.
  • Counterpart for content – For the full RFC822 content of the messages, SMTPDebugIO=4 is responsible.
  • Counterpart for outbound – Outbound SMTP connections are not covered by SMTPDebug; for that, SMTPClientDebug=1 is responsible.
  • Privacy – Addresses, headers, and possibly plain-text commands are logged — observe personally identifiable data.
  • End with set config ...=0 – KB0032184 explicitly mentions that all SMTP debug parameters can be turned off at runtime via set config <name>=0; afterwards restart SMTP/router tasks.

Sources (HCL Product Documentation)