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Sendmail, 3rd Edition by Bryan Costales

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Name

ResolverOptions

Synopsis

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 a minus 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 was 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 the other ...

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