[ARIN-consult] Consultation on Prohibiting Attachments on ARIN Mailing Lists
mysidia at gmail.com
Wed May 2 10:15:58 EDT 2018
On Tue, Apr 24, 2018 at 7:21 AM, ARIN <info at arin.net> wrote:
> ARIN has received a suggestion requesting attachments be prohibited on
> ARIN public mailing lists, including PPML.
> * Question: Should attachments be prohibited on ARIN public
> mailing lists?
No. Well, first of all technically all components of a MIME email
can be described as an attachment: Don't break expected features
without good justification
File attachments have legitimate purposes, for example
as mentioned GPG/PGP message signing -- alternative plaintext versions of
messages sent in HTML or RTF format.
> * Question: If yes, should this include all ARIN public mailing
> lists, or only select lists?
No. Attachments are commonly used with e-mail, and the standard
be supportable, but I suggest regulating file attachment usage for
they pose a risk of harming participants or exclusing people from a
GPG message signing is common: Attachments containing metadata about
of a message are harmless providing they are not useful for
and they are of a reasonable size. 100 Kilobytes is de-minimis.
I'm not sure what resources are available to run ARIN lists, but
these days most services
provide 25-Gigabyte or larger mailboxes, and all the major ESPs
will handle 50 Megabyte objects,
so even 1 Megabyte attachments are widely considered de-minimis.
Example of reasonable restrictions on attachments:
(1) Filter attachment types so as to exclude executables, archive
files such as ZIP/RAR
and documents which are DRM restricted, encrypted, or in a closed or
Example: Microsoft Word Documents are in a closed format; require a proprietary
operating system to view --- Should not be used on a public
discussion list, since not
everyone has the necessary expensive or closed-source software, and
excludes some people from participating in discussion or accessing
information that should be
(2). Replies - When replying to a message on the list; Don't
duplicate the original attachments.
Don't attach files that are available from another source: provide a
link to the source, instead.
(3). Large documents (Bigger than 1 MB) -- Don't send. If it
is highly-pertinent or necessary to
the discussion then send a durable download link instead of attaching
the file into in an e-mail message.
(4). Unrelated Files - Message parts that add up to larger than 100K must
be related to specific on-topic discussion. Do NOT attach a graphic such as
a GIF or JPEG for use in an e-mail signature, for comedic or
graphics should provide diagrams or other visual information related
to the topic.
> John Curran
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