The optional return option.opt file

The optional file
The  file is the one optional file among  the   files; it need not exist, as in its  absence, a reasonable set of (English language) default values will be  used. (Indeed, the English language defaulting for the text controlled by this file is actually a bit more sophisticated than the handling  available via the options in the file.) However, while (unlike the  other   files) its existence is not  required, it is normally desirable to have such a file in  non-English, language-specific directories. The options available for   are listed below. Note that it is critical that any charset parameter setting in the     file be coordinated with the values used (the representation of text  used) in   option values: the charset must  match (except for SUBJECT which,  if non-US-ASCII characters are to be  presented, must be specified as an already RFC 2047 encoded value).

DAY (string), HOUR (string)
Specify the text string to use for  and    substitutions. When the MTA option   (units of days) is  set, the string specified for DAY will be used; when the MTA option    (units of hours) is set, the string specified for  HOUR  will be used. So for instance, in a French language version of  : DAY=jour HOUR=heure Note that the English language default handling, if no DAY and HOUR options are set, is slightly more sophisticated than available with the  option, in that the default English language handling includes a case  distinction: it will substitute Day or Hour in place of  , while substituting "day" or "hour"  in place of. It is important that the actual values be specified in the charset matching the charset parameter configured for  the Content-type: header line in the     file.

DIAGNOSTIC_CODE (string)
The English language default is: DIAGNOSTIC_CODE= Diagnostic code: or for example a French language setting could be: DIAGNOSTIC_CODE= Code de diagnostic :

ORIGINAL_ADDRESS (string)
The English language default is: ORIGINAL_ADDRESS= Original address: Or for example a French language setting could be: ORIGINAL_ADDRESS= Adresse d&#x27;origine :

RETURN_PERSONAL (RFC 2047-encoded string)
Specify the personal name (RFC 822 phrase) to use with the postmaster address. If specified, this will override the Postmaster personal name specified for the source channel via    as well as the  global default specified via the    MTA option.

 SUBJECT (RFC 2047-encoded string)
Specify the value to use on the Subject: header line of DSNs, in RFC 2047 encoded form. So for instance in a French language version of  : SUBJECT==?iso-8859-1?Q?Notification_de_l=27=E9tat_de_remise?= Note that the English language handling, if SUBJECT is not specified, is slightly more sophisticated than available via this option as  different values will be used for different types of DSNs; see  DSN types and their default Subject: field text. It is also possible to specify use of different Subject: values via the   flag of the     mapping table.

REASON (string)
The English language default is: REASON= Reason: or for example a French language setting could be: REASON= Raison :

RECIPIENT_ADDRESS (string)
The English language default is effectively: RECIPIENT_ADDRESS= Recipient address: or for example a French language setting could be: RECIPIENT_ADDRESS= Adresse du destinataire :

REMOTE_SYSTEM (string)
The English language default is: REMOTE_SYSTEM= Remote system: or for example a French language setting could be: REMOTE_SYSTEM= Système distant :

x.y.z (string)
For any possible SMTP enhanced status code that might be reported in a notification, it is possible to configure additional, alternate text to  include in the human-readable portion of the notification. Such text might be chosen to perhaps "better explain" (or at least  provide a description in an alternate language) the corresponding  enhanced status code. For instance: 5.1.0=Il y avait un erreur indefini avec l&#x27;adresse du destinaire. 5.1.1=La boite aux lettres a l&#x27;adresse specifiee n&#x27;existe pas. 5.1.2=Le systeme du destination specifiee dan l&#x27;adresse n&#x27;existe ou est incapable d&#x27;accepter la poste. etc.See RFC 1893 for definitions of the standard meanings of enhanced status codes. Such explanation text, if specified, will be output after the ORIGINAL_ADDRESS information and before the REASON  information as part of the   recipient information  substitution.

Option usage
So in particular, note that  can  re-define the meanings of some of the various    substitutions available in the     files. The available substitution sequences, along with any    options controlling their text effect,  are shown in  return_&#x2a;.txt file substitution sequences.

See also:
 * return_units MTA Option
 * The required full set of DSN type-specific return_...txt files
 * returnpersonal Option
 * return_personal MTA Option
 * DSN language and customization
 * notary_decode MTA Option
 * Customizing DSNs via the return files