Hello,
On Sat, Jun 24, 2023 at 10:18:26AM +0000, Louis Laureys via mailop wrote:
> I was with you until it was revealed you mention a blacklist in
> your response. Sendgrid assumes that the words in the response
> actually have something to do with the reason it's being
> temporarily rejected
The thing that I keep getting hung up on is the unintended
consequences. e.g. I was today years old when I learned that if I
made my mail server say:
450 4.3.2 Local problem - couldn't query foobar blacklist
upon some local error, that could actually be treated as a permanent
failure by the sender and the mail would be silently discarded. I
assume that "blacklist" is not the only such poison pill in
SendGrid's heuristic.
If this sort of thing is common amongst large senders, does that
mean that we should all be combing our 4xx responses for
"triggering" words like "blacklist" and "blocklist"? And how are we
to keep up to date with the heuristics of multiple senders?
If the senders' heuristics were perfect then no one would notice, as
they would only be discarding mail that never would have got
delivered anyway. I realise this is not possible to achieve. But if
senders are going to do this sort of thing, I think their goal needs to
be to keep it as near to unnoticeable as possible, so I don't think
that our response as mailbox providers upon a false positive should
be "well of course if you are going to use the word 'blacklist' then
what did you expect?" That is saying that we accept that the word
'blacklist' should not appear in any context in a 4xx response,
which to me is too bold and is only encouraging more of these
obscure and unpublished interactions.
Cheers,
Andy
--
https://bitfolk.com/ -- No-nonsense VPS hosting
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