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Welcome and Mail Issues
For those folks who have recently joined the mailing list, I am
resending the minutes from the first organizational meeting of this
group at the last IETF in Boulder. The group focused on two main
points, 1) Extensions of SMTP to allow binary files, 2) and
standardizing a mechanism for including body parts.
At the first meeting, the group discussed the RFC 1154 method for
encoding body parts. At the meeting I took an action to contact the
authors of 1154 and discuss the mail extensions effort and
specifically the encoding method of RFC 1154. I contacted David
Robinson, one of the authors of RFC 1154. During the working group
meeting, many felt that the RFC 1154 approach was seriously flawed by
not specifying a content-type field along with encoding field. The
group recognized that a single body type can be encoded several
different ways and did not see how to reconcile that with the
Robinson responded that a basic assumption in RFC 1154 was that
SMTP would continue to have a 7 bit restriction, and all body parts
would use a 7 bit encodings. In this case, a particular encoding type
would imply a content type. The working group has begun with a
different assumption, that eight bit smtp implementations will be
intermixed with seven bit systems. In this situation, there are at
least two different encoding schemes necessary, one for 7 bit and one
for 8 bit systems.
After by announcement to tcp-ip and IETF, I have received several
comments about the specific approach of this working group to
multi-media mail and the groups relationship to various X.400 efforts.
I encourage a discussion on this topic. My main objective is to
standardize on a format and several encodings so user-agents can be
deployed. I have heard of 7+ Multi-media mail implementations, a
number sufficient to demonstrate a real pent up need. This group
would not exist if X.400 was widely deployed or likely to be within
the near term. However, I would like to facilitate easy
interoperation between the two systems. Comments?
Below I have a preliminary list of issues this group should focus on:
1) To what extent should we follow X.400's efforts in currently
defined body parts? With whom should the group interact?
2) Should a message encoding imply a content type, or can these be
independent axis. Implementation is easier with fewer options. A
single encoding with a standard 7bit to 8bit conversion process may be
possible, but the conversion may render text unreadable to unmodified
UA. Other encoding mechanisms like TEX-HEX maintain at least limited
utility between conversions.
3) Some have folks have expressed an interest in maintaining the 7 bit
restriction on text, but allowing a binary mode. I personally feel
this is doing a disservice to international network users who's
character sets are not 7 bit ascii.
4) Should the SMTP extensions include a general purpose option
negotiation sequence? Currently the group is talking about a single
new command to detect modified 8bit, no line length restricted
mailers. Personally I don't see other options needed and would like
to avoid the option negotiation.
Enough for starters.
Reported by Greg Vaudreuil/ CNRI
SMTPEXT Minutes of December 4, 1990
This meeting began as a Birds of a Feather session called by Phill
Gross (CNRI) to discuss two SMTP related proposals. Jan Michael
Rynning (NORDUnet) and Johnny Eriksson (NORDUnet), participating by
telephone, presented a method for transmitting eight bit character
sets over SMTP. A proposal for a standard List-Service syntax for the
Internet was made by Greg Vaudreuil (CNRI). The discussion broadened a
bit and resulted in the formation of a working group to consider
enhancements to SMTP and RFC 822 to allow for body parts.
Rynning's and Eriksson's proposal suggested a mechanism to transmit 8
bit character sets through SMTP. The proposal consisted of 1)
eliminating the 7bit restriction in SMTP, and in cases where 8 bit
SMTP is not implemented 2) proposing a 7 bit encoding for non-8 bit
systems called TEX-HEX. TEX-HEX is a mixture of plain ASCII TEXT and
HEX encoded characters.
The group found the proposal interesting, but primarily as a starting
point for a re-examination of several SMTP issues. There was a
consensus that the group should work to eliminate the 7 bit and 1000
character per line restrictions in SMTP. This will allow easier
sending of binary files. Tom Kessler (SUN) convinced the group that
there was only minor code changes required for sendmail to accept 8
bit ASCII. Kessler further volunteered to author a document
describing the changes to the SMTP protocol. A command "EBIT" was
proposed in the document by Rynning and Eriksson to identify new
mailers. The group agreed that this extension should be considered
for SMTP. An alternate HELO command could be defined to query a mailer
for 8 bit compatibility, such as HELO8.
The working group looked at RFC 1154 for defining encodings of
specific body parts. Some felt that the document has short-comings in
not differentiating between content and the encoding scheme. Greg
Vaudreuil took an action to contact the author as inquire about the
state of that document. The working group felt that establishing body
parts for 822 mail would be a good thing. An outstanding issue
remained concerning the interaction between the various encoding
schemes as the 7 or 8 bit transmission systems.
Rynning and Eriksson took an action to re-write their proposal for
TEX-HEX as a specific encoding and body part to be used with the
John Veizadez (Apple) stopped in to the meeting to brief the group
about Unicos, a universal text encoding scheme developed at Zerox and
Apple. This scheme used 2 octets to represent all known characters.
Chris Myers (U-Wash) explained the list service offered by Washington
University, and explained may of the features of Bitnet's ListServ.
Myers took an action to distribute the listserv document to those in
the group who had an interest. The group did not come to a consensus
on whether to pursue this topic at this time.
Tom Kessler Write a document amending RFC 821 to eliminate the line
length restriction and the 7 bit restriction.
Greg Vaudreuil Determine the state of RFC 1154, and encourage the
author to join in this effort.
Johnny Eriksson and Jan Michael Rynning Rewrite the TEX HEX encoding
document as a specific instance of an RFC 1154 body part.