DSN language and customization

As mentioned in the discussion of the sample DSN of Example non-delivery DSN,  there are a number of localizable, customizable files consulted when  constructing DSNs; these files will be discussed further in  Customizing DSNs via the return files. By default, if no   mapping table  is configured, the   files located in the  IMTA_LANG: directory will be used to generate all DSNs. However, separate sets of   files can be created and  located in separate directories---for localization or site  customization purposes. Indeed, the MTA is distributed with several sets of language-specific   files, and a basic    mapping table (referenced in the mappings file  via file inclusion of the   file) which  selects among the language-specific directories based on language  preference of original message senders. That is, the   mapping table selects, based on any language  preference of the original message sender, a directory in which to find  an appropriate set of   files for generating a  DSN back to that sender.

Probes to the  mapping table have the form: dsn-type&#x7c;source-channel&#x7c;accept-language&#x7c;return-address&#x7c;1st-recipient In the probe,  can be a comma-separated  list including any of ,  ,   ,  ,  ,   ,  ,  ,   ,  ,  , or (as  of MS 7.0u2). The  field will have any values  (possibly a comma-separated list) found on (preferentially) an  Accept-Language: header line in the original message (the message that  the DSN will be reporting on), or if that header line is not present  then from a Preferred-language: header line if present, or failing that  an X-Accept-Language: header line. Note that valid language tag values are discussed in RFC 3066 (Tags for the Identification of Languages).

The pattern (right hand side) of a  entry may set  the   flag to specify the directory (or as of MS 7.0  update 3, a list of comma-separated directories) from which the MTA  should use   files when constructing a DSN. It may also optionally set the  flag to set an override  Subject: header field value to use in the DSN. Note that the default Subject: field values for the various types of DSNs are shown in  Table of DSN types and their default Subject: field text. When both flags are set, the directory argument should be first (left-most), separated by a vertical bar character from the  Subject: header field.

Note: If using  to select an alternate directory of    regardless of DSN type, then it is important  to have a complete set of   files  present in the specified directory. If the MTA cannot locate a   file of the appropriate type in the directory  in which the MTA has been told to find such files, then the DSN will be  constructed omitting that part of the usual structure and the resulting  DSN will therefore look "odd" or "incomplete".

Note: When the MTA has been configured to send copies of notifications to the postmaster (see for instance the    and    channel options), those postmaster copies of the  notification message back to the original sender are copies of the text  sent back to the original sender, and in particular are in the language  selected for the original sender. The postmaster&#x27;s own personal language preferences, if any, are not relevant to these copies; the  purpose of these copies being to be a copy of what the  original sender was sent.

See also:
 * Customizing DSNs via the return files
 * Notification message format
 * langdir MTA Option
 * Pre-defined mapping tables
 * Notification message format