----- Original Message -----
From: "Bud" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, January 01, 2001 12:43 PM
Subject: Re: [IMail Forum] Spam?
> On 1/1/01, Len Conrad penned:
> >>Will IMail look at each message and write an error to the log or
> >>just ignore if it's not coming from a specified IP?
> >
> >Imail get DoS'd by having to look up each and every "RCPT TO:
> >recipient@" in the internal/external Imail user database to decide
> >to accept or reject "recipient@".
>
> That sucks. I figure if Relay For Addresses in turned on, IMail
> should just reject any connection that isn't from an IP in the list.
> Why should it care who the recipient is unless you're using relay for
> users or domains? Or will it still relay mail to users even if the
> mail originates from an IP not on the list?
If it did that, then it wouldn't accept mail from any IP's other then your
own. I'm sure you want incoming mail from more then just your domain :)
Since the incoming attacks are sending mail to your domain, then there's
little Imail can do about it.
The dictionary attacks are a part of life on the Internet. We used to get
10 to 15 thousand rejects over the weekends. We'd just keep putting the
offending IP addresses into the Imail database when we saw the attack coming
in, but that was only a band aid solution.
Getting a gateway between your server and the Internet to filter is the best
method. Len Conrad has a good site on setting up a BSD/Postfix server which
we use, there's also Declude available via a link on the Ipswitch utilities
page. We're using IMgate and the dictionary attacks are pretty much gone.
>
> >And of course, if SMTP logging is turned on, Imail will dutifully
> >log each and every "unknown user" rejection. And as we saw in his
> >logs, if "max RCPT TO: per session" limit is setr and exceeded,
> >rather than disconnect the SMTP brutally, Imail politely rejects and
> >logs each (valid/invalid) recipient@ beyond the limit, continuing
> >the DoS at full SPAM speed.
> >
> >The size of the log files explodes to 100's of mb's, as he reported.
>
> Well. luckily mine are pretty consistently between 800 KB and 1 MB. :)
Some of ours grew to over 100 Mb in a matter of months. You're probably on
one of those "New - 15-Million Fresh E-Mail Addresses" lists, good luck.
[EMAIL PROTECTED]
http://www.kendra.com
> --
>
> Bud Schneehagen - Tropical Web Creations
>
> _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
> ColdFusion Solutions / eCommerce Development
> [EMAIL PROTECTED]
> http://www.twcreations.com/
> 954.721.3452
>
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