Re: [exim] Block tld

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Autore: Mike Brudenell
Data:  
To: exim-users@exim.org
Oggetto: Re: [exim] Block tld
Hi, Emanuel -

The problem is that you are making a huge assumption: that all emails from
any something@*.bid sender address will be spam.

If you're really sure you want to assume this and that there will never be
any legitimate email from such an address then it is better do deny rather
than discard the message. Discard informs the sending machine that their
message was delivered successfully, even though you've actually thrown it
away. This is not good because:

- if a message did happen to be legitimate then the sender is left
thinking their message has reached the recipient when in fact it hasn't;
- if the message is some sort of probe or general spam it can lead to
more messages being sent to your server and wasting your bandwidth and
resources because the spamming software things the address was valid.

In contrast denying a message returns a 5xx "permanent failure" back to the
sender, so:

- a legitimate sender gets to see a response that tells them their
message failed and hasn't reached the recipient, and
- spamming software might (although it's probably unlikely!) give up on
that address in the future.

Rather than making wild assumptions about something@*.bid address all being
spammers, it might be better to use an analysis tool with many weighted
rules such as SpamAssassin. If you're having a particular problem with spam
from *.bid domains add a rule to it with a positive weighting to mark the
message as spam, with at least the chance that the OK characteristics of
legitimate messages might outweigh the spammy bias and allow them through.

Cheers,
Mike B-)

On 24 November 2017 at 12:45, Emanuel Gonzalez <emanuel_gonzalez@???
> wrote:


> Hello.! thanks for your reply.
>
>
> I do not want to block local users but incoming spam.
>
>
> Regards,
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