If an originator-requested-alternate-recipient has been specified by the originator of the message, the message shall be redirected to that alternate recipient in preference to one assigned by the recipients-MD.

videotex, ia5-text-to-telex, telex-to-g3-facsimile, ia5-text-to-g3-facsimile, ia5-text-to-g4-class-1, ia5-text-to-videotex, teletex-to-ia5-text, teletext-to- g3-facsimile, teletex-to-g4-class-1, teletex-to-videotex, videotex-to-telex, videotex-to-ia5-text, or videotex-to-teletex. Other types of explicit-conversion may be defined by future versions of this Recommendation. Explicit-conversion shall be performed as specified in Recommendation X.408.

facsimile-delivery, ia5-terminal-delivery, videotex-delivery or telephone delivery.

cannot be found, a recipient-improperly-specified-abstract-error shall be returned to the originator of the message.

In the absence of this argument, the default physical-forwarding-address-not- requested shall be assumed.

originator of the message. The content-type shall be either built-in or extended.

A built-in content-type may have one of the following values:

external: denotes a content-type which is reserved for use when

interworking between 1988 systems and 1984 systems (see

Recommendation X.419);

One specific value of an extended content-type which has been

defined by this Recommendation is inner-envelope: an extended

content-type that is itself a message (envelope and content),

for forwarding by the recipient named on the outer-envelope to

those named on the inner-envelope (Note that the inner-envelope

and content may be protected by securing the content of the

outer-envelope using the security arguments (see

clauses 8.2.1.1.1.25 to 8.2.1.1.1.32).

Success of a probe does not guarantee that a subsequently submitted message can actually be delivered but rather that, currently, the recipient is valid and the message would encounter no major obstacles to delivery.

determines whether expansion of the specified DL (but not of any nested DLs) would occur.

message has been redirected and the time at which the redirection was

performed. It may be generated by the MTS. A different value of this

argument may be present for each occasion the message was redirected.

appended to the list of intended-recipient-names.

The intended-recipient-name contains the OR-name of an individual or

DL intended-recipient and the time at which the message was redirected

to an alternate recipient.

add recipients to the copy of the message delivered to the recipient

and the time of each expansion. It shall be generated by the MTS if

any DL-expansion has occured.

This argument contains a sequence of OR-names and associated times which document the history of the origin of the subject-message. The first

OR-name in the sequence is the OR-name of the originator of the subject,

and the remainder of the sequence is a sequence of OR-names of the DLs

that have been expanded in directing the subject towards the recipient

(the latter being the same as the DL-expansion-history). It shall be

generated by the originating-MTA of the report if any DL-expansion has

occured on the subject.

The originator-and-DL-expansion-history contains the OR-name of the

originator of the subject and each DL and the time at which the

associated event occured.

the security-policy in force; unable-to-downgrade: the subject could not

be transferred because it could not be downgraded (see Annex B to

Recommendation X.419).

information-type. Deliverable-encoded-information-types also indicates the possible encoded-information-types to which implicit conversion can be performed.

abstract-operation, and are defined in clause 8.3.1.3.1. Except for

permissible-security-context, they may be generated by the MTS-user.

recipient-name: the OR-Address and OR-Directory-name of the

intended-recipient of the token;

defined for a function marked as critical-for-delivery, or shall not deliver

the message or probe and shall return a non-delivery-report with the non- delivery-diagnostic-code set to unsupported-critical-function. A recipient MTS- user shall correctly perform the procedures defined for a function marked as critical-for-delivery or shall return an Unsupported-critical-function

If the MTA or MTS-user cannot correctly perform the procedures defined for a function marked "critical-for-delivery" in a report, then the report is discarded.

-- Upper Bounds

ub-bit-options, ub-built-in-content-type, ub-built-in-encoded-information-types, ub-common-name-length, ub-content-id-length, ub-content-length,

ub-content-types, ub-country-name-alpha-length, ub-country-name-numeric-length, ub-dl-expansions, ub-domain-defined-attribute-value-length,

ub-domain-defined-attributes, ub-domain-defined-attribute-type-length,

ub-domain-name, ub-e163-4-number-length, ub-e163-4-subaddress-length,

ub-encoded-information-types, ub-extension-attributes, ub-extension-types,

ub-generation-qualifier, ub-given-name-length, ub-initials-length,

ub-integer-options, ub-labels-and-redirections, ub-local-id-length,

ub-mta-name-length, ub-mts-user-types, ub-numeric-user-id-length,

ub-organization-name-length, ub-organization-unit-name-length,

ub-organizational-units, ub-password-length, ub-pds-name-length,

ub-pds-parameter-length, ub-postal-code-length, ub-privacy-mark-length,

ub-queue-size, ub-reason-codes, ub-recipients,

ub-recipient-number-for-advice-length, ub-redirections, ub-security-categories ub-security-labels, ub-security-problems, ub-supplementary-info-length,

ub-surname-length, ub-terminal-id-length, ub-tsap-id-length, ub-transfer,

ub-informated-address-length, ub-x121-address-length

Otherwise depending on bilateral agreement or intra-domain policy the current time is noted as the message arrival time and the message is held until expiration of the deferred-delivery-time. The message and timestamp are then returned as result. The procedure then terminates.

domain is added with relay as action. If an arrival time accompanies the message, then delivery deferral has occured and deferred-time is set to the current time and arrival-time is set to the accompanying timestamp value. Otherwise no deferral has occured and the arrival-time is set to the current time.

3) If any of the extension fields is marked critial for relaying but is not semantically understood by the MTA, the procedure returns a report generation instruction. The non-delivery-reason-code is set to transfer-failure and the non-delivery-diagnostic-code to unsupported-critical-function. The procedure then terminates.

Note - This procedure may be called multiple times for any particular message. In such cases, the procedure ignores per recipient instructions generated by previous calls to this procedure which have not yet been acted upon elsewhere.

If the per recipient instruction indicates a delivery failure, then the value for Originator-requested-alternate-recipient is examined for possible recipient substitution. If an alternate recipient is determined and no security parameters are violated, then a redirection instruction is generated and the procedure terminates.

Otherwise the procedure returns a report generation instruction for this recipient. The non-delivery-reason-code and non-delivery-diagnostic-code are those supplied by the Message-delivery or Report-delivery procedure. The procedure then terminates.

recipient. If not, the value for Originator-requested-alternate-recipient is examined for possible recipient substitution. If this reveals no alternate recipient, the the value for alternate-recipient-allowed and any MD specified alternate recipient are considered. If an alternate recipient is determined and no security parameters are violated, then a redirection instruction is generated and the procedure terminates.

Otherwise the procedure returns a report generation instruction for this recipient.

assigned- reassignment-

using the recipient-name from argument 2 to form the intended-recipient-name, obtaining the redirection-reason from argument 4 and containing the Time at which this redirection is performed. The OR-name supplied in the first argument is then substituted for that recipient-name.

3) In the other-actions field the current trace-information, the value redirected is set to true.

4) The message transfer envelope is updated as follows:

recipient-name: replaced

trace-information: indicate redirected

redirection-history: append previous

recipient-name and

redirection-reason

originator-requested-alternate-recipient: deleted if, and only if the redirection-reason indicates originator-requested- alternate-recipient.

8) If the new report request values (determined in step 5) or the DL's local policy will prevent the originator from receiving a requested delivery report from the DL's members, then a copy of the message, with delivery report request instructions for the expanded DL, is constructed and returned along with the message.

9) The procedure returns the revised message and the optional report request and then terminates.

for which 0 < j </=p the associated trace info element is [MD(j) relayed, op(j)] and op(j) = nil. That is, a loop is detected if M arrives at an MD which has already relayed it and each MD afterwards has also relayed it without performing any operation other than routing. If a loop is detected, then the algorithm returns an error indicating the problem, and terminates.

If the report is not to be suppressed, the MTA then replaces the OR-name currently in the report-destination-name field by the OR-name immediately preceding that one in the originator-and-DL-expansion-history field. Thus the report acquires, as a new destination, the next entry back along the chain of entries in the originator-and-DL-expansion-history field:

4) If authentication is not required Messages-waiting is returned if the MTS-user subscribes to the Hold for Delivery element-of-service, and the procedure terminates.

In the case of recipient-name the MTA may use the requested-delivery-method, if present, as an indication of which form of OR-address the directory-name should be mapped to. If a form of OR-address appropriate to the request-delivery-method cannot be found, the recipient-improperly-specified abstract-error is returned by the MTA.

c) If a recipient-name contains an OR-address of a form not appropriate to the requested-delivery-method, if present, the recipient-improperly-specified abstract-error is returned by the MTA.

1) An empty or, if requested, a proof-of-delivery and optional recipient- certificate result passed back from the MTS-user as an indication of successful delivery with no reporting requirements.

2) If a report is required, the main module is invoked and passed the message with per-recipient instructions describing any delivery problems encountered and/or indicating successful deliveries to be reported on.

unable-to-transfer and unsupported-critical-function respectively.

then, subject to the security policy, a report instruction for this recipient is generated. The values of non-delivery-reason-code and non-delivery-diagnostic- code are unable-to-transfer and secure-messaging-error respectively.

6) If delivery is barred by restrictions imposed in a previously invoked Register or Delivery-control abstract-operation, then, subject to the security- policy in force, the MAT will hold the message pending the lifting of the applicable restriction(s).

8) If restricted delivery is enforced, and the recipient falls in the category of unauthorized senders, then a report instruction is generated for this recipient. The value of non-delivery-reason-code is set to restricted- delivery. Processing then terminates for this recipient.

unable-to-transfer and unsupported-critical-function respectively.

security-policy, then the report is discarded.

2) If Report delivery is barred by restrictions imposed in a previously invoked Register or Delivery-control abstract-operation, then, subject to the security-policy in force, the MAT will hold the report pending the lifting of the applicable restriction(s). Restrictions are established by arguments of the Delivery-control or Register abstract-operation as described in

clause 8.3.1.3.1.