Mapping paranoia MTA option

Access mapping table MTA options:  (integer)
(New in Messaging Server 7.0) Since access-check mappings such as the recipient address    mappings,  the    mapping, the   mapping, the   mapping, the   mapping, and new in Messaging Server 7.3-11.01 the   mapping table, and new in 7.0.5 the    mapping table and   mapping table, use vertical bars as  delimiters, issues can arise when externally provided material such as  envelope From or To addresses themselves contain vertical bars. The  MTA option is intended to provide  various tools to handle such issues.

Giving the  MTA option a nonnegative value will cause any vertical bars in the externally supplied portions of various mapping input strings to be replaced in the mapping probe with the character whose ASCII value is given by this option. (Attempting to set  to a positive value greater than 127 will result in the value 124, the default, being used.) That is, the "regular",  field-separating, vertical bars will still be present, but a vertical  bar within an external field (such as within an address) will be  replaced by the specified character. A negative value will cause the vertical bar to simply be dropped entirely from the probe. The default value for this option is 124, the ASCII value for vertical bar, which  causes vertical bars to be left untouched.

Note that many mapping tables where   is relevant also have a feature for  testing whether a vertical bar was originally present in externally  supplied probe fields; use of   to replace the original  vertical bar characters does not affect such testing: the test flag is  set based on the original presence of a vertical bar character,  regardless of whether it is later replaced due to.

See also:
 * Access mapping table MTA options
 * Access mapping tables
 * AUTH_REWRITE mapping table
 * BURL_ACCESS mapping table
 * GROUP_AUTH mapping table
 * AUTH_ACCESS mapping table
 * MILTER_ACTIONS mapping table
 * MILTER_MACROS mapping table
 * Sieve external lists