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Re: More then 2800 spams from the list...

On Tue, 20 Mar 2018 08:52:48 +0100
<tomas@tuxteam.de> wrote:

> "never" is too strong a word. This is a corollary of the fundamental
> law "all generalizations suck".
How do you determine the exceptions? 

A SMTP server, by default, accepts email only for recipients which have
an account on it. Aliases can be added, but on the whole, there is no
mechanism for a 'catch-all' mailbox. Someone has to deliberately add
some code to make such a thing happen. This has even been true of
Exchange for the last few versions. It's generally not difficult, but
it's not there out of the box. 

There won't be any NDR spam if all the invalid email goes into one
particular account for a human to examine. The problem occurs if and
when a later SMTP server attempts to download and deliver this email to
multiple people who don't exist.

A salesman might argue that if only valid accounts are accepted, he
might miss a valuable sale because of a mis-spelled email address. In
other words, no price is too high for the rest of the Internet to pay
for him to get one more lead, no matter how poor. I'm not a salesman, so
I see things differently.

Things aren't as bad as they used to be, probably 90% of what my mail
server refused was once NDR spam. I could see in the logs the same dozen
obviously deliberately incorrect email addresses every day, sometimes
several times a day. This has reduced with the decline of small (and
large!) businesses running their own private SMTP servers but
downloading their mail from a single shared external POP3 account,
which used to be a very common practice.


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