9.6. Sendmail -d

The -d command line option turns on debugging options internal to Sendmail. These options are of the form " class1[-class2].level", where class1 and class2 are numbers representing groups of similar debugging information and level is a number representing the level of detail you want to see for those classes. Higher numbers indicate greater detail. The debugging goes to standard output. The -d command line option takes a comma-separated list of these class1[-class2].level specifications, as in the following:

-d0.4,21.3

• Says that for debugging class 0 we want to see any debugging messages that are at levels 4 and below; also, for class 21 we want levels 3 and below.

-d0-40.4

• Says that for debugging classes 0 through 40, we want to see any debugging messages that are at levels 4 and below.

The degenerate case is " -d" with no argument following it; this is the same as saying " -d0-99.1" that is, select level-1 debugging detail for every debugging class. This is almost never going to be what you want.

Debugging classes and levels vary somewhat from vendor to vendor, since individual vendors would have had their own special porting problems getting Sendmail to run on their computer, and they likely added debugging output that focused on those special problems. Some vendors are less generous; they provide Sendmail binaries with no internal debugging at all for these systems, the -d command line option is a no-op. If...