Re: [vps-mail] Question about Sendmail/Spammers

["Bennett Lanford" <ben@xxxxxxxxxxxxx>]

On Tue, April 5, 2005 4:00 am, Andy McKell, FOCUS Internet said:
>
> I've seen this spamming technique on VPS1's as well - mailing directly to
> the server ignoring the MX records. I originally assumed all such mail was
> spam, but not always so.

Another common technique involves domains with multiple MX records.
Instead of trying the MX server with the lowest MX number, spammers
program their spam generator to use the server with the *highest* number.
Their reasoning (often correct) is that "backup" MX servers will have
weaker filtering than the primary MX server: backup servers will receive
mail that the primary MX server would block.  Since primary MX servers
automatically accept mail from their backup MX servers, sending mail to
the backup MX servers is much more successful.

(In this day and age fewer and fewer domains are finding backup MX servers
necessary, fortunately)


-- 
Bennett Lanford <ben@xxxxxxxxxxxxx>

There are 10 kinds of people: those that understand binary and those that
don't.
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