Debugging sendmail

System Management Guide: Communications and Networks

Debugging sendmail

There are a large number of debug flags built into the sendmail command. Each debug flag has a number and level, where higher levels mean print more information. The convention is that levels greater than nine print out so much information that you would not want to see them except for debugging a particular piece of code. Debug flags are set using the -d flag as shown in the following example:

debug-flag:     -d debug-list 
debug-list:     debug-flag[.debug-flag]* 
debug-flag:     debug-range[.debug-level] 
debug-range:    integer|integer-integer 
debug-level:    integer

For example:

-d12            Set flag 12 to level 1 
-d12.3          Set flag 12 to level 3 
-d3-17          Set flags 3 through 17 to level 1 
-d3-17.4        Set flags 3 through 17 to level 4

Available debug flags are as follows:

-d0	General debugging.
-d1	Show send information.
-d2	End with finis( ).
-d3	Print the load average.
-d4	Enough disk space.
-d5	Show events.
-d6	Show failed mail.
-d7	The queue file name.
-d8	DNS name resolution.
-d9	Trace RFC1413 queries.
-d9.1	Make host name canonical.
-d10	Show recipient delivery.
-d11	Trace delivery.
-d12	Show mapping of relative host.
-d13	Show delivery.
-d14	Show header field commas.
-d15	Show network get request activity.
-d16	Outgoing connections.
-d17	List MX hosts.