What do you mean by mail gateway?

A mail gateway is responsible for sending & receiving. Your exchange server 
should receive it's mail from the mail gateway and send through the mail 
gateway. Is that not how it is set up?

S

From: Paul Everett [mailto:[EMAIL PROTECTED]
Sent: Tuesday, July 29, 2008 5:43 PM
To: MS-Exchange Admin Issues
Subject: Mail Gateway vs Exchange

Hi guys and gals,

I'm moving this over from the NT Admin forum since it seems to be purely an 
Exchange issue.  I'm still looking for guidance on why and what my DC is trying 
to send out port 25.
Please read from the bottom.
Thanks,

Paul

================================================

Yes, all the mail seems to be flowing out just fine.  I'm getting "rely denied" 
ndr's for a few domains and I seem to be listed with Barracuda still, but no 
other issues I'm aware of.
I'm showing connections using port 25 on both "local address" and "foreign 
address".  The entries which are on "local address" most of the "state" values 
are Time-wait with a pid of 0.  The occasional pid of smssmtp.
All the foreign addresses showing pid of smssmtp.

I must not understand how mail is supposed to flow.  I assumed that the mail 
flowed into and out of the Mail Gateway (my DC), and maybe it did (and still 
trying), but my Exchange Server seems to be sending it fine since that is the 
only ip allowed out in my firewall (for smtp traffic).
When I installed Ninja on my Exchange Box I uninstalled Symantec for Exchange 
(or whatever it's called).  My plan was to also take Symantec Mail Security for 
SMTP off the DC, but decide that it was an extra layer of Security that wasn't 
hurting anything.  I can't remember if we did anything to change the flow of 
outgoing email at that time or not.

Paul
________________________________
From: Tim Evans [mailto:[EMAIL PROTECTED]
Sent: Tuesday, July 29, 2008 11:15 AM
To: NT System Admin Issues
Subject: RE: blacklists

And those are connections from the DC to the firewall (and not the reverse)? 
Something is misconfigured or you misunderstand how mail is supposed to flow. 
Is all the mail flowing outbound that is supposed to be?

...Tim

From: Paul Everett [mailto:[EMAIL PROTECTED]
Sent: Tuesday, July 29, 2008 8:05 AM
To: NT System Admin Issues
Subject: RE: blacklists

It's the Symantec Mail Security for SMTP.  Now what?

________________________________
From: Tim Evans [mailto:[EMAIL PROTECTED]
Sent: Tuesday, July 29, 2008 9:54 AM
To: NT System Admin Issues
Subject: RE: blacklists

It sounds like either something is misconfigured, your DC is infected  or you 
don't correctly understand how mail is supposed to flow in your network.  Get 
on your DC and run netstat -no and looks for connection to port 25 on your  
firewall. Then look up the PID in task manager to see what process on the DC is 
sending the mail.

...Tim

From: Paul Everett [mailto:[EMAIL PROTECTED]
Sent: Tuesday, July 29, 2008 6:00 AM
To: NT System Admin Issues
Subject: RE: blacklists

Everything is looking good this morning, as far as our email is concerned and 
so far still off the blacklists.  In "host watch" of the Watchguard System 
Manager, I am getting numerous (hundreds/minute) outbound Filtered-SMTP 
"denies" from my DC (which is my mail gateway).  I thought mail was just going 
thru there one-way (incoming).
Mail in ->WG Firewall -> DC (Symantec Mail Security for SMTP) -> Exchange 
Server -> WG Firewall -> Mail out.
Could there just be a misconfiguration on my DC?

Paul

________________________________
From: Paul Everett [mailto:[EMAIL PROTECTED]
Sent: Monday, July 28, 2008 6:52 PM
To: NT System Admin Issues
Subject: RE: blacklists

They are proxy's.  I have two defined.  One called SMTP and it has the incoming 
set From: any, To: WG ip -> DC (mail gateway).  The outgoing tab is disabled.
The other proxy is called Filtered-SMTP.  It's Incoming is Disabled and the 
Outgoing is set From: Any, To: Any.  I change this From: Exchange ip, To: Any.
I've never been able to figure logging on the WG.  I can never find the logs 
and for email, I can't find where to set the address??  The WG interface seems 
so simple, but it really makes me feel like an idiot at times.

Hope this is good enough damage control for tonight.  I'll be back in the am to 
check things and do more investigating.

Thanks for all the suggestions.

Paul

________________________________
From: Dennis Hoefer [mailto:[EMAIL PROTECTED]
Sent: Monday, July 28, 2008 6:24 PM
To: NT System Admin Issues
Subject: RE: blacklists

Open Policy Manager on the Watchguard 700, you will have either a proxy or 
filter policy for SMTP.  On the "Outgoing" tab, set From: to the IP address of 
your mail server and To: to "all"  The default rule is all to all, which will 
allow traffic from port 25 to pass from any machine on your network.  By 
setting From: to only your mail server IP, you will block any internal machines 
that may be attempting to send SMTP traffic on their own.  You can also set the 
rule to log denied traffic which will quickly identify internal machines that 
are attempting to use port 25.

Configuration is a little different on the newer Watchguard boxes, but should 
be pretty straight forward on the 700.  If the problem persists, then you're 
back to a relay problem or compromised mail server.

Dennis

________________________________
From: Paul Everett [mailto:[EMAIL PROTECTED]
Sent: Monday, July 28, 2008 4:54 PM
To: NT System Admin Issues
Subject: RE: blacklists
"Set the mail server so that it only accepts mail from your exchange server" 
They are one and the same.  My DC is actually my Mail Gateway between the WG 
and Exchange.
"Block port 25 at the firewall for all but authorized systems (mail server)."  
Any idea how to do this on a Watchguard 700?

Thanks


________________________________
From: Tim Evans [mailto:[EMAIL PROTECTED]
Sent: Monday, July 28, 2008 5:47 PM
To: NT System Admin Issues
Subject: RE: blacklists

Sounds like you may have an infected client on your network that is sending 
outbound spam. Block port 25 at the firewall for all but authorized systems 
(mail server). Set the mail server so that it only accepts mail from your 
exchange server. That should get things cleared up enough so that you'll stay 
off the blacklists and give you some time to hunt for the guilty party.


...Tim

From: Paul Everett [mailto:[EMAIL PROTECTED]
Sent: Monday, July 28, 2008 2:35 PM
To: NT System Admin Issues
Subject: blacklists

We've been finding ourself on some blacklists since last week and have 
basically shut us down.  Specifically Spamhaus and Barracuda's.
I'm not sure if I have an infected computer on my network sending spam or not.  
I've requested my ip removed from the blacklists several times, but after a day 
or two I'm back on.  I've got a window to post this question before it happens 
again.  Here's what I have.
One Domain, two locations connected via PTP T1 (Adtrans).  All Internet access 
is at one location where I have my Mail Server 2003 (Ninja) and a Watchguard 
Firewall.  All clients (about 200) running Symantec AV.
I don't have really the tools or knowledge to run any packet capture software 
(or anything else) to determine if I have an owned machine, but while I am 
working on that is there any way to close my firewall to outbound mail traffic 
while still letting my Exchange out?  Do infected computers send email thru 
port 25 like Exchange?  If so, can I block that port and change the port 
Exchange uses to send?  If so, how?
This may take me awhile, but I'd like to stay off the blacklists in the mean 
time.

One thing I've done is installed Zone Alarm on my pc to see if I can catch any 
of my local computers scanning my network.  After the install it asked if I 
wanted my Outlook to act as a Server.  The info button showed that it should be 
ok to do, but I said "no".  My email seems to be working but I keep getting 
notifications that ZA is blocking internet access to my computer from my mail 
server.  This is probably nothing.

Thanks for any suggestions.

Paul Everett
IS Dept.
Lee Mental Health Center
239-791-1551

"Lee Mental Health Center, Inc. providing services through Ruth Cooper Center 
for Behavioral Health Care and VISTA Behavioral Crisis Services.  Visit our 
website at www.leementalhealth.org to learn more."

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