Challenge/Response for 100% spam reduction?

[ThorGoLucky]

Is Zimbra considering implementing a challenge/response system so that any email received by Zimbra must be registered with Zimbra? I've seen this feature on hosted email systems. It's restrictive but the spam situation is getting out of hand.

[dkarp]

I've spoken with a few people who had to deal with sending mail to such a system. They absolutely HATE it. Some go so far as to refuse to send mail to such hosts.

You can, of course, file an enhancement request in bugzilla for this.

[scottnelson]

Agreed! Business use of a c/r system is "just poor" form really.

I have pretty much got rid of 99% of my spam:

1. 66/20 vs. stock 75/33
2. http://www.rulesemporium.com/rules.htm
Stock, OEM and adult rules
I even upped the points for .gif's in the "stock scams" rule from 1.66 to 4.66
3. RBL's ( Can't stress using these enough!!!! )

4. DSPAM is now at 1 vs. stock 0.5

I know, one of those YMMV things but, you can get pretty darn close really.

My .02 worth anyway.

[anand]

scottnelson, how hard was it to add SARE rules to a Zimbra install? Can you please document it or file a bug if we are making it difficult to add SARE rules to a Zimbra install or if we are blowing away your SARE additions on an upgrade. Thanks.

[mjfleck2000]

Originally Posted by scottnelson

Agreed! Business use of a c/r system is "just poor" form really.

I have pretty much got rid of 99% of my spam:

1. 66/20 vs. stock 75/33
2. http://www.rulesemporium.com/rules.htm
Stock, OEM and adult rules
I even upped the points for .gif's in the "stock scams" rule from 1.66 to 4.66
3. RBL's ( Can't stress using these enough!!!! )

4. DSPAM is now at 1 vs. stock 0.5

I know, one of those YMMV things but, you can get pretty darn close really.

My .02 worth anyway.

Please, how did you up the points for the gif scams? ... that is, what file did you modify?


I have started using greylisting at our mail gateway with RBL's. This helps alot but dang those gif's. If I could up the score on gif's, I would be a hero here at our clinic.

Mike

[scottnelson]

Originally Posted by anand

scottnelson, how hard was it to add SARE rules to a Zimbra install? Can you please document it or file a bug if we are making it difficult to add SARE rules to a Zimbra install or if we are blowing away your SARE additions on an upgrade. Thanks.

To add a rule or rules:
Pick a rule from this page: http://www.rulesemporium.com/rules.htm

Lets say you want to last rule on page called: Stock scams
http://www.rulesemporium.com/rules/70_sare_stocks.cf

ssh in as you,
then 'su'
then 'su zimbra'
cd to '/opt/zimbra/conf/spamassassin'
then 'wget www.rulesemporium.com/rules/70_sare_stocks.cf'

then, 'zmcontrol stop'
then 'zmcontrol start'

Done

Last Zimbra version upgrade I did, ( 3.12 to 3.14 ) I think the new rules were left in place but don't remember now.
There is an automatic SARE rules update script called "RulesDuJour" but I have made "point" changes in certain rules so, don't want anything updated automatically overiding my changes. I just check the site once a week or so to see what's changed, if any.

Rules I use from this site are:

70_sare_adult.cf
70_sare_oem.cf
70_sare_stocks.cf
72_sare_bml_post25x.cf

Is this what you needed?

Scotty

[scottnelson]

Originally Posted by mjfleck2000

Please, how did you up the points for the gif scams? ... that is, what file did you modify?


I have started using greylisting at our mail gateway with RBL's. This helps alot but dang those gif's. If I could up the score on gif's, I would be a hero here at our clinic.

Mike

Hey, anything to make you a hero eh? ;-)

ssh in as you,
then 'su'
then 'su zimbra'
then,
vi /opt/zimbra/conf/spamassassin/70_sare_stocks.cf

( If you don't have this rule, see the post right above this )

Then
'/SARE_GIF_ATTACH'

Default is: 0.75

I changed mine to 4.75
Also, I changed 'SARE_GIF_STOX' from 1.66 to 4.66

Since I am at 66/20, put's it over the top but still delivered to 'Junk'
folder so people can move to different folder if turns out to be legit.
Just have to look at the header info for the ones that are getting through
and up the point value a bit until you get a good balance.

One of those YMMV things....... ;-)

Scotty

[jdell]

How did you change the default DSPAM points from 0.5 to 1? I'm not seeing where that is set.

Also, can you use 'zmamavisdctl restart' or 'zmantispamctl restart' to reload the spam rules rather than the full zmcontrol stop/start routine?

Thanks for the tips!

[anand]

Originally Posted by scottnelson

Is this what you needed?

Scotty

yes, thanks much!

[phoenix]

There's also an automatic update for these rules by using Rules_Du_Jour, there's a wiki here: Rules_Du_Jour