Minimal FAX address format in Internet Mail (RFC2304)
Original Publication Date: 1998-Mar-01
Included in the Prior Art Database: 2019-Feb-15
Internet Society Requests For Comment (RFCs)
This memo describes the MINIMAL addressing method and standard extensions to encode FAX addresses in e-mail addresses. [STANDARDS-TRACK]
Network Working Group C. Allocchio Request for Comments: 2304 GARR-Italy Category: Standards Track March 1998
Minimal FAX address format in Internet Mail
Status of this Memo
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
Copyright (C) The Internet Society (1998). All Rights Reserved.
This memo describes a simple method of encoding PSTN addresses of facsimile devices in the local-part of Internet email addresses.
As with all Internet mail addresses, the left-hand-side (local- part) of an address generated according to this specification, is not to be interpreted except by the MTA that is named on the right-hand-side (domain).
Since the very first e-mail to fax gateway objects appeared, a number of different methods to specify a fax address as an e-mail address have been used by implementors. Two major objectives for this were
- enable an e-mail user to send faxes from his/her e-mail interface;
- enable some kind of "fax over e-mail service" transport, to reduce the costs of fax transmissions, and use the existing e-mail infrastructure.
Allocchio Standards Track [Page 1]
RFC 2304 Minimal FAX address format March 1998
This memo describes the MINIMAL addressing method and standard extensions to encode FAX addresses in e-mail addresses, as required in reference . The opposite problem, i.e. to allow a traditional numeric-only fax device user to access the e-mail transport service, is not discussed here.
All implementations supporting this FAX over e-mail address format MUST support as a minimum the specification described in this document. The generic complex case of converting the whole PSTN addressing in e-mail is out of scope in this minimal specification: there is some work in progress in the field, where also a number of standard optional extensions are being defined.
In this document the formal definitions are described using ABNF syntax, as defined into . We will also use some of the "CORE DEFINITIONS" defined in "APPENDIX A - CORE" of that document. The exact meaning of the capitalised words
"MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", "OPTIONAL"
is defined in reference .
2. Minimal Fax address
The "service-selector" defined in section 2 of reference  for the fax service is:
service-selector = "FAX"
The minimal addressing for the fax service also requires support for a "qualif-type1" element (see section 2 of reference ). This element is an OPTIONAL element of the fax address, but its support, when present, is REQUIRED:
qualif-type1 = "/" t33-sep "=" sub-addr
t33-sep = "T33S"
sub-addr = 1*( DIGIT )
Thus, the minimal specification of a fa...