Topic: SME as spam gateway

[jvels]

Hi

Does anybody have experience with use a SME contribs as spamfilter gateway?

I have  M$ Small Business Server and consider to set a SME up as firewall, and spam/virus filter gateway there are sending mails to the M$ Small Business Server, is it possibel?

[Mjohnson]

Hi jvels..

First, I think this topic should be in the wrong forum.  Admin, maybe this can be moved??

Second, I have been running SME as a spam and antivirus filter front end to Exchange for several years now.  I presume you are running SME in server only mode.  At that point merely redirect port 25 (SMTP) to the SME server.  In SME's server manager, at the email tab, provide the address of your SBS server in the Delegate Mail Servers.  That's about it.

You can set your configurations for Spamassassin and ClamAV via the Server Manager.  You can also set up RBL / SBL, but that requires command line setup.  If you perform a forum search, there are several threads on setting that up.

SME works great in that role.

MJ

[Amir Inbar]

hi Mjohnson

I have another setup at one of my customers office.
The setup is :
1. SBS 2003 server that is connected to the router - providing calendar and contacts server.
2. SME server rc3 connected to the router - providing mail, antivisrus and antispam server.

the SME is an upgrade i "forced" them to use since they had a lot of trouble with the mails when it was handled by SBS.

Now they seem to have problems related to Outlook client - when they create a new mail everything works fine and the mail is being sent by SME. When they reply or forward a message - sometimes Exchane "takes over" and the mails are sent by Exchange which is not active as an smtp server thous generating error messages and the mail returns to sender.

The outlook clients are set to use SME as default mail server.

Maybe you have some expirience with that and you can help ?

TNX

Amir

[Mjohnson]

amir,

Your problem does not sound like it is an SME issue, but rather an Outlook/Exchange issue.  I have not had any issues as you have experienced.

Couple of possible ideas to look into:

1.  I use Exchange as the SMTP outbound server.  Works very well, no issues to report.  You may wish to try that.

2.  Check your Outlook user profile.  If you are not using Exchange, then it should not connect to the Exchange Server (i.e. email client mode rather than Corporate mode).  It sounds like the Outlook Client is defaulting to the Exchange Server for replies, forwards.  What has me puzzled is that you say it only happens sometimes.  

3.  I am presuming you are using Outlook 2003 or so, not Outlook Express.  

4.  You could have a look at the site http://www.slipstick.com  That site has a lot to offer for Outlook / Exchange issues.

[Amir Inbar]

TNX

[jvels]

how should I config SME for sending the mail to the SBS, after scaning the mails

[MSmith]

jvels - I have several SME boxes doing exactly what you're describing in front of Exchange Server.  It's in the manual ... in the server manager, under the Email heading, the Exchange Server's IP should be listed as the "Address of internal mail server".  In this configuration, SME will reject virus-infected emails as default and optionally tag and/or reject spam.

To avoid any mail loops I have set the Exchange Server's outgoing SMTP to the ISP's SMTP server.

[ksc133]

hi folks,

using sme 7 as anti-spam gateway sounds good.
can it also filter virus emails as well?

thanks

[skydivers]

hi folks,

using sme 7 as anti-spam gateway sounds good.
can it also filter virus emails as well?

thanks

Yes it does!

[ksc133]

hi skydivers,

thanks for your fast response.

another question,
eg: i'm using exchange 2000 for my email and SME 7 is infront of it filtering emails.
can SME 7 also filter outgoing spams and virus from LAN as well?

is there anyway that i can see and release those spams captured by SME 7 box incase some legitmate mails get caught inside?

thanks

[ksc133]

hi folks

i set my SME 7 anti-spam as below:
Spam tagging level = 2
spam rejection level =3
i run a spam test of 100 spams to my SME7
it did rejected 70% of the spams
the other 20% was tagged as "****spams****" their score was around 2.2 to 2.9.
the other 10% score was below 2

my questions:
1) how to fine tune the anti-spam to a rejection level of 2.5?
2) i did a legimate email test from yahoo mail(not spam email) and the score was 2.8! how to allow legimate emails from yahoo to SME7?
3) is the anti-spam filter updated everyday?
4) how about the clamAV definations?

thanks

[mmccarn]

I recommend enabling the 'auto learn' capability of the Bayes filter - this will allow your system to fine-tune its spam sensing capabilities over time.

You don't see much progress at first, but it gets better and better as the system learns what email you like / don't like.

Here's a link to an old post on how I set it up: http://forums.contribs.org/index.php?topic=33824.0.

You may also want to look into the 'greylisting' plugin for qpsmtpd.  I haven't used greylisting on SME, but I have clients whose ISPs use it - it seems very effective.