Okay,
I took the plunge and set my options to 'local host' only. Then I stopped
and restarted the imail services.
It appears that everything is working okay.
For all of you who were so eager to test my server's open relay, can you try
it again? It looks like the email is still working, now I need to make sure
that it really is stopping these spamsters.
Bradley Dean
[EMAIL PROTECTED]
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Len Conrad
Sent: Tuesday, July 25, 2000 12:11 AM
To: [EMAIL PROTECTED]
Subject: RE: [IMail Forum] Help - I'm being attacked
>I don't want to do SMTP Auth, I don't think my (L)users could handle it.
Well, then how will they "handle it" when they can't send mail from their
accounts on your server because your Imail server is blacklisted as spammer
source or open relay?
>My worry is that by local host it means my IP block.
False worry. "local host" in that phrase means an virtual mail host
defined in Imail. It has nothing to do with your ip address or ip block
directly. "relay for local (mail) host" means Imail will relay any msg
where the sender, valid or spammer, is using a "MAIL FROM:
[EMAIL PROTECTED]" address. The weakness is that anybody can setup
their mail client as @BradleyBox.com and spam through your effectively
"open relay". You must assume this will happen. It is very weak mail
security.
>So if a user is dialed
>up to their ISP, Mindspring or whoever, and then they use Outlook to send
>and receive their email it will not let them send it. Is this not true?
If you set "relay for local hosts" and your users dial-up through another
ISP and send mail to your Imail server with "mail from:
[EMAIL PROTECTED]", then your Imail will accept and relay the mail for
them.
But a lot of the big ISP's are blocking access to port 25 to all ip's
except their own SMTP servers, just so their DUL's, "dial-up lines"
(includes cable and DSL subscribers, generally) can't spam from DUL and get
the ISP blackholed. ie, the DUL must relay outgoing mail through the ISP's
SMTP server, and, furthermore, we even had last week an example where the
ISP required the DUL to use a sending address like "Mail From:
sender@ISPdomain" (GTE as ISP, iirc). ie, one of your users dialing into
GTE, couldn't send mail to your server anyway.
Len
http://BIND8NT.MEIway.com: ISC BIND 8.2.2 p5 installable binary for NT4
http://IMGate.MEIway.com: Build free, hi-perf, anti-spam mail gateways
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