ResolverOptions
Tune DNS lookups All versions
The ResolverOptions
option allows you to tune the way DNS lookups are
performed. The forms of this option are as
follows:
O ResolverOptions=arg ... ← configuration file (V8.7 and later) -OResolverOptions="arg ..." ← command line (V8.7 and later) define(`confBIND_OPTS',`arg ...') ← mc configuration (V8.7 and later) -oI"arg ..." ← command line (V8.6 and later) OIarg ... ← configuration file (V8.6 and later) OIbool ← configuration file (deprecated) -oIbool ← command line (deprecated)
The arg
is one or more
arguments that allow you to tune the behavior of the
name server. The arg
arguments are identical to the flags listed in
resolver(3), but you omit the
RES_
prefix.
For example, RES_DNSRCH is expressed as DNSRCH. A
flag can be preceded by a plus or minus sign to
enable or disable the corresponding name server
option. If no pluses or minuses appear, the name
server option is enabled just as though a plus were
present. Consider the following:
O ResolverOptions=+AAONLY -DNSRCH
These turn on the AAONLY name server option
(Authoritative Answers Only) and turn off the DNSRCH
name server option (search the domain path). If the
ResolverOptions
option is omitted entirely, the default is for the
DNSRCH, DEFNAMES, and RECURSE name server options to
be enabled and all others to be disabled. Thus, for
example, DNSRCH is always enabled unless you
specifically turn it off.
Beginning with V8.7 sendmail, the
special string HasWildcardMX
can be listed along with ...
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