Re: Length of the local part of e-mails

[Harald Alvestrand <harald@xxxxxxxxxxxxx>]

Julien ÉLIE wrote:
> Hi,
>
> Section 7.2 of USEAGE mentions that a newsgroup name is limited to 66 
> characters.
> Section 3 of RFC 3696 mentions that the local part of an e-mail 
> address is limited
> to 64 characters.
RFC 3696 has status "informational".

RFC 2822 states:

4.5.3.1 Size limits and minimums

  There are several objects that have required minimum/maximum sizes.
  Every implementation MUST be able to receive objects of at least
  these sizes.  Objects larger than these sizes SHOULD be avoided when
  possible.  However, some Internet mail constructs such as encoded
  X.400 addresses [16] will often require larger objects: clients MAY
  attempt to transmit these, but MUST be prepared for a server to
  reject them if they cannot be handled by it.  To the maximum extent
  possible, implementation techniques which impose no limits on the
  length of these objects should be used.

  local-part
     The maximum total length of a user name or other local-part is 64
     characters.

(fwiw, the maximum length of an X.400 O/R address was on the order of a 
kilobyte)

> Yet, section 3.5.1 of USEPRO has this note:
>
> 3.5.1.  Forwarding Messages to a Moderator
>
>    NOTE:  Deriving the email address of the moderator of a group is 
> outside
>    the scope of this document.  It is worth mentioning, however, that 
> a common
>    method is to use a forwarding service that handles submissions for 
> many
>    moderated groups.  For maximum compatibility with existing news 
> servers,
>    such forwarding services generally form the submission address for
>    a moderated group by replacing each "." in the <newsgroup-name> 
> with "-"
>    and then using that value as the <local-part> of a <mailbox> formed
>    by appending a set domain.
>
>
> Shouldn't a warning be put here?  Because the compatibility is not 
> optimum
> with mailers when a moderated newsgroup contains 65 or 66 characters.
Reality check: How many newsgroups currently exist that have names 
longer than 64 characters?
> Or will it be handled by USEAGE?
The editing of USEPRO is finished for this generation, so USEAGE is the 
least unlikely alternative.

                      Harald