Sendmail Installation and Operation Guide
SMM:08-83
versa. If -N is specified it never tries without a null byte and if -O is specified it
never tries with a null byte. Setting one of these can speed matches but are never
necessary. If both -N and -O are specified, sendmail will never try any matches
at all -- that is, everything will appear to fail.
-ax
Append the string x on successful matches. For example, the default host map
appends a dot on successful matches.
-Tx
Append the string x on temporary failures. For example, x would be appended if a
DNS lookup returned "server failed" or an NIS lookup could not locate a server.
See also the -t flag.
-f
Do not fold upper to lower case before looking up the key.
-m
Match only (without replacing the value). If you only care about the existence of
a key and not the value (as you might when searching the NIS map
"hosts.byname" for example), this flag prevents the map from substituting the
value. However, The -a argument is still appended on a match, and the default is
still taken if the match fails.
-kkeycol
The key column name (for NIS+) or number (for text lookups). For LDAP maps
this is an LDAP filter string in which %s is replaced with the literal contents of
the lookup key and %0 is replaced with the LDAP escaped contents of the lookup
key according to RFC 2254.
-vvalcol
The value column name (for NIS+) or number (for text lookups). For LDAP
maps this is the name of one or more attributes to be returned; multiple attributes
can be separated by commas. If not specified, all attributes found in the match
will be returned. The attributes listed can also include a type and one or more
objectClass values for matching as described in the LDAP section.
-zdelim
The column delimiter (for text lookups). It can be a single character or one of the
special strings " \n" or " \t" to indicate newline or tab respectively. If omitted
entirely, the column separator is any sequence of white space. For LDAP maps
this is the separator character to combine multiple values into a single return
string. If not set, the LDAP lookup will only return the first match found.
-t
Normally, when a map attempts to do a lookup and the server fails (e.g., sendmail
couldn't contact any name server; this is not the same as an entry not being found
in the map), the message being processed is queued for future processing. The -t
flag turns off this behavior, letting the temporary failure (server down) act as
though it were a permanent failure (entry not found). It is particularly useful for
DNS lookups, where someone else's misconfigured name server can cause prob-
lems on your machine. However, care must be taken to ensure that you don't
bounce mail that would be resolved correctly if you tried again. A common strat-
egy is to forward such mail to another, possibly better connected, mail server.
-D
Perform no lookup in deferred delivery mode. This flag is set by default for the
host map.
-Sspacesub
The character to use to replace space characters after a successful map lookup
(esp. useful for regex and syslog maps).
-sspacesub
For the dequote map only, the character to use to replace space characters after a
successful dequote.
-q
Don't dequote the key before lookup.
-Llevel
For the syslog map only, it specifies the level to use for the syslog call.
-A
When rebuilding an alias file, the -A flag causes duplicate entries in the text ver-
sion to be merged. For example, two entries: