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Groups > comp.os.linux.networking > #2774

Re: ping Moe Trin

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Moe Trin <ibuprofin@painkiller.example.tld.invalid> wrote in
news:slrnlhfl3f.cij.ibuprofin@fermi.phx.az.us: 

> On 5 Mar 2014, in the Usenet newsgroup comp.os.linux.networking, in
> article <slrnlhf8fq.81f.grahn+nntp@frailea.sa.invalid>, Jorgen Grahn
> wrote: 
> 
>>Thad Floryan wrote:
> 
>>> buck wrote:
> 
>>>> I am searching for an RFC that says an Email header may contain a
>>>> blank SENDER.  I'm sure I read that the SMTP server must not 
reject
>>>> messages  where the SENDER is blank, but darned if I can find it
>>>> now.
> 
> I wonder if you are referring to section 6.4 of RFC5321. which is 
sort
> of based on "The Robustness Principle" (see RFC1122 section 1.2.2)
> originally attributed to Jon Postal:
> 
>                 "Be liberal in what you accept, and
>                  conservative in what you send"
> 
>>> Googling "RFC that says an Email header may contain a blank 
SENDER"
>>> without the quotes provides what you seek.
> 
>>Which of the hits, and will the answer be "yes" or "no"?  I'm asking
>>because his question is ambiguous: is he talking about the "Sender:"
>>header or about any header providing some kind of information about
>>the sender (From:, Sender:, possibly others)?
> 
> I'll agree that the question is ambiguous.   "Sender:" isn't a
> "required" header in all cases, and may be missing in many cases.
> "From:" on the other hand...
> 
>>Personally I'd check RFC 5322 section 3.6.2.
> 
>   6854 Update to Internet Message Format to Allow Group Syntax in 
the
>        "From:" and "Sender:" Header Fields. B. Leiba. March 2013.
>        (Format: TXT=20190 bytes) (Updates RFC5322) (Status: PROPOSED
>        STANDARD)
> 
>   Abstract
> 
>    The Internet Message Format (RFC 5322) allows "group" syntax in
>    some email header fields, such as "To:" and "CC:", but not in
>    "From:" or "Sender:".  This document updates RFC 5322 to relax 
that
>    restriction, allowing group syntax in those latter fields, as 
well
>    as in "Resent-From:" and "Resent-Sender:", in certain situations.
> 
> On the other hand,
> 
>    The Internet Message Format, as far back as RFC 822 [RFC0822], 
has
>    always required a usable address to appear in the "From:" header
>    field of messages in order to allow replies to be sent.  To this
>    end, the syntax of messages, up to and including the current
>    specification [RFC5322], has required the use of the mailbox
>    address form in the originator ("From:" and "Sender:") fields of
>    messages and has specifically forbidden the use of the group
>    address form, which permits an empty list of addresses (that is, 
an
>    address list with no address included that might be used for a
>    reply). 
> 
>    However, the use cases for the "From:" field have evolved.  There
>    are numerous instances of automated systems that wish to send 
email
>    but cannot handle replies, and a "From:" field with no usable
>    addresses would be extremely useful for that purpose.
> 
> But you also want to look at the SMTP transaction (RFC5321, section
> 3.3) about the "MAIL FROM" dialog.
> 
> So "buck", care to clarify the question?
> 
>         Old guy
> 

Let me read the RFCs referenced in replies to my question, after which 
I
will reply more carefully. 

Meantime, from a moral standpoint I wish to insist that if the sender
refuses to identify that I may discard the message without having
violated any internet standard. -- 
buck

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ping Moe Trin buck <buck@private.mil> - 2014-03-05 19:26 +0000
  Re: ping Moe Trin Thad Floryan <thad@thadlabs.com> - 2014-03-05 13:44 -0800
    Re: ping Moe Trin Jorgen Grahn <grahn+nntp@snipabacken.se> - 2014-03-05 22:15 +0000
      Re: ping Moe Trin Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2014-03-06 01:50 +0000
        Re: ping Moe Trin buck <buck@private.mil> - 2014-03-06 07:19 +0000
          Re: ping Moe Trin David Brown <david.brown@hesbynett.no> - 2014-03-06 09:38 +0100
          Re: ping Moe Trin Richard Kettlewell <rjk@greenend.org.uk> - 2014-03-06 09:54 +0000
          Re: ping Moe Trin William Unruh <unruh@invalid.ca> - 2014-03-06 17:43 +0000
        Re: ping Moe Trin Rick Jones <rick.jones2@hp.com> - 2014-03-06 19:23 +0000
          Re: ping Moe Trin buck <buck@private.mil> - 2014-03-06 20:33 +0000
            Re: ping Moe Trin Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2014-03-07 02:52 +0000
              Re: ping Moe Trin "Charlie Gibbs" <cgibbs@kltpzyxm.invalid> - 2014-03-07 14:09 -0800
                Re: ping Moe Trin Jorgen Grahn <grahn+nntp@snipabacken.se> - 2014-03-08 20:58 +0000
                Re: ping Moe Trin Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2014-03-09 01:53 +0000
          Re: ping Moe Trin Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2014-03-07 00:22 +0000

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