Re: best practices for fighting spam with Debian?
Daniel Pocock <daniel@pocock.pro> wrote:
> A key point to consider for any filtering is the user experience when a
> legitimate message is not delivered.
> This includes the following:
> - does the sender know their mail was not delivered and do they get a
> reasonable explanation? I've heard there are spam filters who give a
> "user doesn't exist" error which is somewhat disrespectful to genuine
> senders.
I can understand the reason for this: Don't give the spammers any
indication if an address is valid. But I have yet to see any solid
evidence that it makes a difference if one responds with a "500 Your
was classified as SPAM." or "500 User does not exist".
Far more "damage" is done by clicking on any (so called) unsubscribe
links in SPAM mails.
> If the messages end up in a junk folder the sender has no idea.
> Personally I think it is better to graylist or reject messages with a
> basic explanation like "Your message could not be delivered because of
> local policy"
Exactly.
> - does the recipient have to wade through a junk mail folder looking
> for things that went there by mistake? In this case, I feel the spam
> problem hasn't really been solved at all, the user still has to do the
> work sifting through spam to find the ham and it is still a painful
> overhead for them.
Some people want to operate this way.
> In some countries and certain industries a lot of companies have
> simply started using cloud solutions from some of the large vendors.
> They tend to get all the messages from companies in their industry on
> the same platform, but I noticed that one of them was incorrectly
> putting mail that had come from one of my Debian mail servers into
> their junk folder. Their IT manager spent a lot of time chasing the
> vendor to find out why this was happening and they never got any valid
> answer. It was frustrating for them and for people sending the mail.
> The vendor would just say that they have to keep their policies
> secret.
Also exactly the reason why we $here decided to do the heavy lifting
ourselves instead of buying a ready-made appliance.
S°
--
Sigmentation fault. Core dumped.
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