[asterisk-users] OT: Explain where mailing list bouncing comes from ?

James B. Byrne byrnejb at harte-lyne.ca
Fri Jun 16 16:37:58 CDT 2017

On Fri, June 16, 2017 12:28, Tim S wrote:

Whether it is intentional or not these messages railing against the
list operators has a decided tone of condescension which is not
warranted.  The fact of the matter is that DMARC is broken by design
and the unpleasant effects that adoption of it has on mailing-list
traffic were well hashed out on the ITEF mailing lists before it was
adopted anyway.  What was predicted there has come to pass.

DMARC conflicts with the existing SMTP RFCs in several ways, none of
which I will elaborate here but all of which may be discovered by
perusing the relevant threads on the ITEF mailing lists.  Some mailing
list management software, notably Mailman, since has been modified to
'work around' the problems with DMARC if so configured by the list
owners.  But only at the cost of violating the SMTP RFCs themselves.
Do not take my word for it.  Raise these issues on the Postfix mailing
list and discover what response you get from Viktor and Wietse.

The driving force behind DMARC was YAHOO's shoddy security of their
own users' accounts.  With Hotmail and similar ilk close behind. It is
a completely inappropriate, and in my opinion ill-thought-out,
technical solution to what is essentially an internal security problem
at some email providers, albeit very large ones.  In general it is an
example of what is called 'externalising your costs'.

The appropriate answer has been provided: lose the
gmail/hotmail/yahoo/freemail account and administer your own domain
for personal email. Configure the spf and dkim settings on your own
domain as required to suit your needs and not those of someone else.

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James B. Byrne                mailto:ByrneJB at Harte-Lyne.ca
Harte & Lyne Limited          http://www.harte-lyne.ca
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