null
Provide a never-found service V8.7 and later
The null
database-map type is an internal service that always
returns a failed lookup.
Normally, the null
type is used only internally. It can, however, be
useful when used to replace another database-map
type so that it can force failure without causing an
error. Consider, for example, a tiny configuration
file that does not need the use of the
aliases facilities. One way
to declare aliases would be like this:
O AliasFile=null:
This tells sendmail to use the
null
type for
looking up aliases. Therefore, no aliases will ever
be found.
None of the K
command switches can be used with the null
database-map type.
If you try to use any, they will be silently
ignored. No debugging switch is available to watch
this null
database-map type.
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