HP-UX Mailing Services Administrator's Guide

Sendmail 8.13.3
New Features in Sendmail 8.13.3
Chapter 3 115
The first two forms describe an IPv4 or IPv6 socket listening on a certain
port at a given host or IP address. The last form describes a named
socket on the file system at the given path.
Following is an example of a socket map that specifies a remote endpoint:
KmySocketMap socket inet:12345@127.0.0.1
If multiple socket maps define the same remote endpoint, they share a
single connection to this endpoint.
DNS Maps
The dns map is an internal database map available to perform DNS
lookups. You can use the following K configuration command to declare
the dns map:
Kdnslookup dns -Rlookup-type
where dnslookup specifies the name of the map using DNS.
The dns-type database map is primarily used for dnsbl and endnsbl
features.
You must always include the -R switch, which specifies the DNS resource
record type to lookup, in the dns map declaration.
Sendmail 8.13.3 supports the following types of resource records: A, AAAA,
AFSDB, CNAME, MX, NS, PTR, SRV, and TXT. A map lookup returns only one
record. For certain types of records, such as MX records, the return value
can be a random element of the list due to randomizing in the DNS
resolver.
Table 3-1 describes the different -R values in the dns database map.
Table 3-1 Supported DNS Queries
-R Value Description
A Returns IPv4 address records for the host (RFC 1035)
AAAA Returns IPv6 address records for the host (RFC 1886)
AFSDB Returns an AFS server resource record (RFC 1183)
CNAME Returns the canonical name for the host (RFC 1035)
MX Returns the best MX record for the host (RFC 1035)