sendmail, 4th Edition

The type

Recall that the type^[338] portion of the K configuration command follows the name:

Kname type args

Note that whitespace between the name and the type can be a joined indented line, which allows commenting and improves readability:

Kname             # Why this name
        type      # Why this type
        args      # and so on

The type declares which sort of database map to use. It must be one of the types listed in Table 23-2.

Table 23-2. Possible K command types

Type	§	Versions	Description
arith	arith on page 898	V8.10 and later	Perform arithmetic computations.
btree	btree on page 901	V8.1 and later	A db(3) form of database.
bestmx	bestmx on page 902	V8.7 and later	Look up the best MX record for a host.
dbm	dbm on page 903	V8.1 and later	Really ndbm supplied with most versions of Unix.
dequote	dequote on page 904	V8.6 and later	Remove quotation marks.
dns	dns on page 905	V8.12 and later	Look up information using DNS.
hash	hash on page 908	V8.1 and later	A db(3) form of database.
hesiod	hesiod on page 909	V8.7 and later	MIT network user authentication services.
host	host on page 910	V8.1 and later	Internal table to store and look up hostnames.
implicit	implicit on page 911	V8.1 and later	Search for an aliases database entry.
ldap	ldap (was ldapx) on page 912	V8.8 and later	The Lightweight Directory Access Protocol (LDAP).
ldapx	ldap (was ldapx) on page 912	V8.9 and earlier	Replaced by ldap.
macro	macro on page 925	V8.10 and later	Store a value into a macro ...