Start/notes.ini Parameters/MAILDEBUG

MAILDEBUG

🛠️
Parameter: MAILDEBUG
Short description: Enables detailed tracing of mail processing (router, mail.box) on the server console.

Profile

Parameter
MAILDEBUG
Category
Logging / Debug
Component
Server
Available since
9.0.1
Supported versions
9.0.1, 10.0, 11.0, 12.0, 14.0, 14.5, 14.5.1
GUI equivalent
notes.ini only (no GUI)
Possible values
0 = off (default), 1 = basic, 2 = verbose

Description

For diagnosing mail routing issues (stuck mails, routing loops, faulty delivery paths), MAILDEBUG provides additional information directly on the server console / in the console log: recipient resolution, routing decision, next hop, success / error status. Level 1 is sufficient for most cases; 2 produces very verbose trace output – with correspondingly higher overhead.

Example configuration

MAILDEBUG=1

Notes & pitfalls

  • Console and log volume increase noticeably – disable again after diagnostics.
  • Takes effect after a router restart (tell router quit / load router).
  • Sensitive recipient / subject information can appear in the trace – handle logs accordingly.
  • Pairs with Log_MailRouting, MAIL_LOG_TO_MISCEVENTS, and Log_Connections for SMTP diagnostics.