Hi
Thanks for the info. As far as I know the secondary is not trusted by the primary and yet it is acting like it is in that the symptoms you mention below are exactly what is happening - mail being delivered to the secondary and then being sent straight to the primary and somehow bypassing the spam checks. It is also being used for dictionary attacks as I have found thousands of .gse files that are undeliverable messages to non-existant user accounts. I have no users setup on the secondary server - it is simply spooling and forwarding mail. SMTP security is fine and it is not being used for any other relaying.
Diarmaid
-----Original Message-----
From: "Kevin Coveney" <[EMAIL PROTECTED]>
Sent 8/1/2007 6:35:39 PM
To: [email protected]
Subject: Re: [IMail Forum] Mail coming through secondary mailserver seems to be skipping AntiSpam filters
Most likely your secondary mail server is accepting all the mail for your domains and not spam filtering it just spooling it. If your Primary mailserver "trusts" this box it will bypass the spam filtering. This will also kill any of the dnsbl lookups and other server tests since the mail is being seen as coming from your own network at the other location unless your spam test can be programmed to bypass the last hop. Also, if this secondary server is not validating users and outright rejecting - it can open your server up to dictionary attacks via your secondary plus having the secondary deal with processing and traffic of handling all bounce messages. -Kevin Diarmaid Mac Aonghusa wrote: > Hi > > I have recently added a secondary mailserver for all of the domains we host > mail for at a separate physical location. It all seems to be working fine > (we already had a 30 minute outage and it successfully spooled several > thousand emails and then delivered them all within about 20 minutes once the > main server came online) however we do have a problem with a huge increase > in spam and having looked at the headers of some of them it seems that mail > that is getting delivered through the secondary server is getting forwarded > onto the primary server and is NOT being scanned for spam. I have checked > our whitelist to ensure that the IP address of the secondary mailserver is > not listed as a Trusted address. > > Does anyone have any ideas what might be causing this? Using Imail Server > 2006 - Windows Server 2003. > > Thanks > > _______________________ > Diarmaid Mac Aonghusa > Fusio.net > > To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html > List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ > Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ > To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
