The host database-map type is a special internal
database used by sendmail to help resolve
hostnames. It is fully described under the $[ and $] operators in
Section 23.4.3.
Only a few database-map switches are available with the
host type, and they are listed in Table 23-15.
Table 23-15. The host database-map type K command switches
-a
|
-a
|
Append tag on successful match
|
-d
|
See this section
|
The res_search( ) _res.retry
interval (V8.12 and above)
|
-D
|
-D
|
Don't use this database map if DeliveryMode=defer
|
-m
|
-m
|
Suppress replacement on match
|
-r
|
See this section
|
The res_search( )
_res.retries limit (V8.12 and above)
|
-S
|
-S
|
Space replacement character
|
-T
|
-T
|
Suffix to append on temporary failure
|
-t
|
-t
|
Ignore temporary errors
|
The -D database switch should probably always be
used with this type on sites that have dial-on-demand connections to
the Internet. It prevents host lookups when the
DeliveryMode option (DeliveryMode)
is set to defer.