Enhancement #2681

Wrong default thresholds for antispam

Added by Alessio Fattorini over 7 years ago. Updated over 7 years ago.

Status:CLOSEDStart date:
Priority:NormalDue date:
Assignee:-% Done:

100%

Category:nethserver-mail-filter
Target version:v6.5-final
Resolution: NEEDINFO:No

Description

Fresh install, antispam tresholds are those:
Spam threshold = 6.2
Deny message spam threshold= 6.9

Spam treshold is too high, probably too false-negative with this, the best is 5 (refs: http://taint.org/2008/02/29/155648a.html)
Deny message spam threshold is too low, could be dangerous especially on newly installed systems. My proposal is set to 10 at least, maybe 12 is better.

Associated revisions

Revision e7780087
Added by Davide Principi over 7 years ago

Adjusted default spam thresholds. Refs #2681

History

#1 Updated by Alessio Fattorini over 7 years ago

  • Subject changed from Default threshold for antispam are wrong to Wrong default thresholds for antispam

#2 Updated by Davide Principi over 7 years ago

On a production mail server we have 

 SpamTag2Level=5
 SpamKillLevel=9

Maybe a lower default is good while Bayes filters are not effective. From Spamassassin wiki

The bayesian classifier can only score new messages if it already has 200 known spams and 200 known hams.

Any suggestion?

#3 Updated by Davide Principi over 7 years ago

  • Status changed from NEW to TRIAGED
  • % Done changed from 0 to 20

#4 Updated by Davide Principi over 7 years ago

  • Status changed from TRIAGED to ON_DEV
  • Assignee set to Davide Principi
  • % Done changed from 20 to 30

#5 Updated by Davide Principi over 7 years ago

  • Status changed from ON_DEV to MODIFIED
  • Assignee deleted (Davide Principi)
  • % Done changed from 30 to 60

Test case

On a fresh installation the new default values are:

 SpamTag2Level=5.0
 SpamKillLevel=15.0

Upgrade notes

To reset spam thresholds to their new default values:

    # config setprop amavisd SpamTag2Level 5.0 SpamKillLevel 15.0
    # signal-event nethserver-mail-filter-save

#6 Updated by Davide Principi over 7 years ago

  • Status changed from MODIFIED to ON_QA
  • % Done changed from 60 to 70

In nethserver-testing:
nethserver-mail-filter-1.1.4-2.0gite7780087.ns6.noarch.rpm

#7 Updated by Giacomo Sanchietti over 7 years ago

  • Assignee set to Giacomo Sanchietti

#8 Updated by Giacomo Sanchietti over 7 years ago

  • Status changed from ON_QA to VERIFIED
  • Assignee deleted (Giacomo Sanchietti)
  • % Done changed from 70 to 90

Properties are correct after upgrade:

[root@localhost amavisd]# config delprop amavisd SpamKillLevel
[root@localhost amavisd]# config delprop amavisd SpamTag2Level
[root@localhost amavisd]# signal-event nethserver-mail-filter-update 
[root@localhost amavisd]# config show amavisd
amavisd=service
    AdminNotificationStatus=disabled
    AvailableDecoders=mail,asc,uue,hqx,ync,F,Z,gz,bz2,lzo,rpm,cpio,tar,deb,zip,7z,rar,arj,arc,zoo,lha,doc,cab,tnef,exe
    BlockAttachmentClassList=Exec
    BlockAttachmentCustomList=doc,odt
    BlockAttachmentCustomStatus=disabled
    BlockAttachmentStatus=enabled
    EnabledDecoders=mail,asc,uue,hqx,ync,F,Z,gz,bz2,lzo,rpm,cpio,tar,deb,zip,7z,rar,arj,arc,zoo,lha,doc,cab,tnef,exe
    MaxProcesses=4
    RecipientWhiteList=
    SenderBlackList=
    SenderWhiteList=
    SpamCheckStatus=enabled
    SpamDsnLevel=20
    SpamKillLevel=15.0
    SpamSubjectPrefixStatus=disabled
    SpamSubjectPrefixString=***SPAM*** 
    SpamTag2Level=5.0
    SpamTagLevel=2.0
    TCPPorts=
    VirusCheckStatus=enabled
    status=enabled

Marking as VERIFIED.

#9 Updated by Davide Principi over 7 years ago

  • Status changed from VERIFIED to CLOSED
  • % Done changed from 90 to 100

In nethserver-updates:
nethserver-mail-filter-1.1.5-1.ns6.noarch.rpm
nethserver-antivirus-1.0.7-1.ns6.noarch.rpm

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