Prev: Exchange quota service "RPC error occured"
Next: Auto Accept Agent: Issue with configuration
From: Craig on 4 Apr 2008 11:16
I have enabled the IMF and we are also running Antigen v9 on this
box. I noticed that lately I have been receiving a lot of spam from
addresses like jj(a)mydomain.com (where mydomain.com represents our
internal email domain name). As the messages appear to come from our
email domain the IMF doesn't block them and even though the content of
the message flags it with an SCL of 9, Outlook doesn't move it to my
Junk Email folder.

I received an email from a Microsoft Forefront engineer on how to
block internal spoofing on our Exchange server and looked into
implementing his suggestion. The document basically says to go into
the Sender Filtering tab and check on the "Filter messages with blank
sender" box and to add "@mydomain.com" to the Senders window. This
didn't sound correct to me, and sure enough, in testing this
configuration the server would not allow me to send SMTP mail from my
valid email address (myname(a)mydomain.com). When I tried to do so
using Outlook Express I received the message that "The message could
not be sent because the server rejected the sender's e-mail address".

My question is, can the Exchange server be configured to allow SMTP
sending if the address exists on our server, but block any messages
for email addresses that do not exist on our server? Alternatively
are there other ways to block these spoofed emails on our server?

Feedback appreciated...
From: Oliver Moazzezi [MVP] on 4 Apr 2008 11:29
It would have worked as the engineer suggest if using MAPI. Why are you
using SMTP and sending using Outlook Express? Is there a reason for this?

Oliver


From: Craig on 4 Apr 2008 11:38
On Apr 4, 11:29 am, "Oliver Moazzezi [MVP]"
<o.moazzez...(a)spamfreenet.co.uk> wrote:
> It would have worked as the engineer suggest if using MAPI. Why are you
> using SMTP and sending using Outlook Express? Is there a reason for this?
>
> Oliver

Unfortunately I still have two users on dial up and they are using
POP3 and SMTP for their email. Thanks to Apple I also have a couple
of users using IMAP and SMTP for email.

Craig
From: Oliver Moazzezi [MVP] on 4 Apr 2008 11:52
>Unfortunately I still have two users on dial up and they are usingPOP3
> and SMTP for their email. Thanks to Apple I also have a couple
>of users using IMAP and SMTP for email.

Aha, so that makes sense then. There's nothing you can do with the
configuration of Exchange then to leviate this issue.

You will have to put an appliance (server with mail product) that will do
this for you.

Oliver


From: Craig on 4 Apr 2008 12:01
On Apr 4, 11:52 am, "Oliver Moazzezi [MVP]"
<o.moazzez...(a)spamfreenet.co.uk> wrote:
> >Unfortunately I still have two users on dial up and they are usingPOP3
> > and SMTP for their email.  Thanks to Apple I also have a couple
> >of users using IMAP and SMTP for email.
>
> Aha, so that makes sense then. There's nothing you can do with the
> configuration of Exchange then to leviate this issue.
>
> You will have to put an appliance (server with mail product) that will do
> this for you.
>
> Oliver

That's what I was afraid of. I'm hoping to eventually get the dial up
user onto a broadband connection but with the iPhone becoming more
prevalant I seem to be handcuffed using IMAP and SMTP. :-(
 |  Next  |  Last
Pages: 1 2
Prev: Exchange quota service "RPC error occured"
Next: Auto Accept Agent: Issue with configuration