Report from Introducing Suse Linux Enterprise in Jakarta

I was visiting Introducing Suse Linux Enterprise 10 Seminar on Wednesday, 7th March 2007 in Jakarta and hoping that I can see and learn new features from Suse Linux. The Agenda in the invitation card is really promising, but the time frame is to tight, start from 9:00 AM to 01:00 PM with a lot of topics to discuss. It's weird, but because I'm a big fan of Linux (I use Open Suse at home), so I decided to go.

The seminar delayed almost an hour, just because (I think) the projector didn't work. The seminar start an hour later after the projector was replaced with another one.

Now, the speaker (from Malaysia), maybe because of the delay, start to jump in live demo about High Availability Data Center with Xen and Heartbeat. The speaker doesn't even start with a presentation about it. He talk about if one server having a problem, and the other one will take over and also try to restart to server which in problem (if possible). Most of us never heard of Xen and Heartbeat, so jumping to the live demo is really confusing.

Then he start talk about new topic, Thin Client. This is good topic, and he explain a little beat slower, so most of us can understand, at least I can. Thin clients works similar like Windows Terminal Server, where we can use stocks of old pc to do simple task. The thin client doesn't even need a hard disk to boot, it boot directly from the network, and can be use for simple task like data entry.

The final topic is about SLED (Suse Linux Enterprise Desktop), but in this session he mostly talk about the new 3D desktop (xgl) that I think is direct competitor with Windows Vista 3D. After I see the demonstration, I think that the xgl is far more better than Windows Vista. While not that hardware hungry like Windows Vista, it can produce good and smooth 3D graphics desktop. I'm not sure how improvement in graphical user interface like 3D desktop can help you to enhance productivity, but it's a nice touch.

He also talk about the new Open Office 2.0 that can run VBScript macro. He also give us a demonstration that Calc (similiar with Ms Excel) can run Ms Excel file with macro, and it running fine. If this true, than we really can migrate from Ms Windows to Linux. I have to try this with my own stocks of macro.

One of the best thing about MS Office is their Ms Excel, and the best thing about Ms Excel is their macro.

Personally, I have a lot of macro to help my job, mostly for reporting to my boss. Every month giving the same report, macro is a big help. Without macro, I will spend hours just to prepare a report. With macro, I can finish it less than 15 minutes. If Open Office 2.0 really can understand and run windows macro, at least 80% of it, its really a big help. It will give people more strong point to migrate from Ms Windows to Linux.

The good thing about Suse Linux compare with Red Hat that Suse Linux only have two versions of Linux, Desktop (client) and Server. That's it.
While Redhat have many versions of Linux, there are clients, server, advance server... I lost count. But every linux is good, the different is the support. If you buying linux, make sure that you have a good support.

I believe linux is the future.

How to configure sendmail as a gateway

This is a simple how to about how to configure sendmail to act as a mail
gateway.

This how to will only talk about 3 files: access, mailertable and
relay-domains.

File relay-domains NOT included in sendmail distribution (at least in my
CentOS distribution), you have to create it manually.
All files (at least in my CentOS) located in directory /etc/mail

Access file
First, we put our host and our network to be able to relay through our
server.
localhost.localdomain RELAY
localhost RELAY
127.0.0.1 RELAY
192.168.1 RELAY
192.168.2 RELAY

If you use GreetPause feature, you can put no waiting for local email.
GreetPause:localhost 0
GreetPause:192.168.1 0
GreetPause:192.168.2 0

If you using DNSBL, and want to skip one or two domains from DNSBL check,
you can use this
Connect:friendlydomain.com OK

Now for the big part.
Put all the domain that you want to relay BUT put it as REJECT. This way by
default all emails to that domain will be rejected unless we specify
otherwise - in this case OK.

indomino.net REJECT
blablabla.org REJECT
something.edu REJECT

user1@indomino.net OK
user2@indomino.net OK
user3@indomino.net OK

user1@blablabla.org OK
user2@blablabla.org OK

user1@something.com OK

Finish. For access file, you can use make -C /etc/mail to 'compile' it.

Mailertable file
Now put this entry in mailertable, so sendmail will know to where it will
route the emails.
indomino.net smtp:smtp.indomino.net
blablabla.org smtp:[192.168.1.25]
something.edu esmtp:[192.168.1.50]

Finish. Do make -C /etc/mail to 'compile' it.

Relay-domains file.
Most forgotten file, I think because it's not included in most
distribution. You have to create it manually. Simply as type touch
/etc/mail/relay-domains to create the file.

Now type all the domain that you want to relay.
indomino.net
blablabla.org
something.edu

Finish. Now restart the server.

Steps to stop SPAM

There is a good article about steps that we can use to prevent spam, you
can find the very good article in here
http://www.spamhaus.org/effective_filtering.html.

Personally, I use spamhaus as my primary DNSBL. It never let me down. Off
course there are some legitimate emails that being block by spamhaus, very
few, and that's not my problem. :).
I believe email administrators and ISP admin must protect they servers and
their network from spammers.

These is my configuration to stop spam:

1. DNSBL test in mta level.
I use sendmail as my mta server, and activated DNSBL in sendmail. Why put
DNSBL in mta level? Because it can stop a lot of spam before it transferred
to our mail server. But because it will stop few legitimate emails, I try
to put 'not so aggressive' DNSBL like sbl from spamhaus (actually I use
sbl-xbl.spamhaus.org).

2. Greetpause
Great new feature from sendmail. This way all emails (except if we put some
conditional) will be forced to wait for HELO or EHLO command from the mta
server. If the email doesn't bother to wait for HELO or EHLO command, the
we don't bother to receive, we simply kick it.

3. Mailscanner
Great software. Nothing more to say. You can download the latest version in http://www.mailscanner.info. In Mailscanner I activate these
features:

3.1. Spamassassin
A must. In new version of spamassassin there a script called sa-update to update builtin spamassassin rules, you can use cron job to make it run automatically every day.
You can add additional rules for spamassassin, most of them are in http://www.rulesemporium.org, additional rules can be automatically updated with smart cron job called rules_du_jour.

3.1.1. DCC + Razor
Inside the Spamassassin, I turn on both DCC and Razor. Increase the spam
score enough to make it a spam.

3.1.2. Bayes
Help a lot to stop more spam. I create two mail box, one for spam and one
for ham (non spam). Each day, a cron job will learn from each mail box, and
learn it as spam or ham.

3.2. Clamav (for check viruses)
Every mail server need antivirus. Clamav is the best there is, and free.

3.3. Another DNSBL test (to increase score)
This DNSBL actually will increase the spam score.

That's are my configurations. Hope that will help you to create your own
configuration for battle against spam.

Lotus notes client 7.01 for Linux

Maybe some of you remember when WE - Lotus Notes user and also Linux lovers
- ask when will the IBM release Lotus Notes client for Linux? The answer is
simple, NEVER because it will need to redesign and recoding the software
completely, and even IBM doesn't have resources for that.

But now, there is.

IBM finally launching Lotus Notes client for Linux since June 2006. Thanks
to eclipse powerful software, IBM engineers able to run Lotus Notes client
as eclipse plug-in.

Some user report that the client is take a lot of memory because it run
under the eclipse software. While eclipse software it self take a lot of
memory. Users hope that maybe in future, respectful IBM engineers will able
to make eclipse software much thinner and lighter and of course faster. So
Lotus Notes client able to run under it with better performance.

Right now, only passport customers are able to download the software. There
is no trial version - yet.

Well, at least we have hope now. Not that simple answer NEVER.

Linux is the future, as simple is that. And IBM knew it, that why despite
the NEVER answer, IBM still looking for a way to make Lotus Notes run under
linux. Thanks IBM for great and wonderful software's.

About MailScanner

One word about MailScanner, great.
It a tools that, well almost eliminate all your emails problem. Virus, and spam email will be eliminated. Not 100% though, but hey, nothing can.
MailScanner it a perl script that rely on other tools and software to eliminate virus and spam. It heavily rely on Spamassassin to check if the email is spam or not. For viruses, it can detect and use multiple anti virus installed, for example you can use clamav and f-prot for the same time.

MailScanner have many rules to simplify it setting. It have whitelist, blacklist, file name rules, file type rules and many others. For rbl, we can put it in mta level or in MailScanner. For example, we can put a safe rbl (which almost ONLY block spam) in mta level, and we put more agressive rbl in mailscanner. Very flexible.

You can configure MailScanner in most known mta server, like sendmail, postfix and exim. It very easy to install, my first try take me about 2 hours. And the server is up and running.
With the default configuration, it more than enough. to handle spam, but you tweak it if you like. The configuration is self explain, very easy to understand.

Conclusion.
MailScanner it a very usefull software. If you are a mail administrator, its a must. The features is more powerfull than most paid software.

I will write more about mailscanner, very interesting software.
You can learn more about mailscanner at http://www.mailscanner.info