Mail gateway server with amavis on CentOS 8

[Nikolaos Milas]

On 17/12/2020 12:31 μ.μ., Nikolaos Milas wrote:

> I have been using a mail gateway with 
> postfix/amavis/clamav/spamassassin for many years on CentOS 6.
>
> I am now struggling to build a new system on CentOS 8 with the same 
> components (and the same configuration) to replace the original one, 
> but it is quite different from the original, so I will appreciate your 
> guidance.

Hello,

Merry Christmas to all!

Following my above post, I would like to send an update and ask on bayes 
database migration.

I have managed to answer most of my own questions and now I have a 
working setup.

During the migration I have migrated the bayes db from the older (CentOS 
6) setup to the new (CentOS 8) server as follows:

On original Server:

    # su amavis
    sh-4.1$ sa-learn --dbpath '/var/amavis/var/.spamassassin' --backup >
    bayes-mailgw3.db

On new server (after scp transfer and chown to amavis:amavis):

    # su amavis
    sh-4.4$ pwd
    /var/spool/amavisd
    sh-4.4$ sa-learn --dbpath /var/spool/amavisd/var/.spamassassin/ --clear
    sh-4.4$ sa-learn --dbpath /var/spool/amavisd/var/.spamassassin/
    --restore bayes-mailgw3.db
    sh-4.4$ ls -la var/.spamassassin/
    total 8620
    drwx------. 2 amavis amavis    4096 Dec 21 15:23 .
    drwx------. 4 amavis amavis    4096 Dec 16 16:53 ..
    -rw-------. 1 amavis amavis  659456 Dec 21 15:23 bayes_seen
    -rw-------. 1 amavis amavis 9490432 Dec 21 15:23 bayes_toks

I would expect this db to be working fine and I anticipated similar 
filtering results on both servers, but sending a test email to both 
servers, produces different results (note: I have restarted amavisd 
after db migration):

On original server:

    score=12.436 tag=-999 tag2=3.4 kill=5.2 tests=[ARCHIVE_PASSWORD=5,
    BAYES_999=2.7, BAYES_99=3.7, HTML_MESSAGE=0.001, MIME_HTML_ONLY=0.1,
    NO_FM_NAME_IP_HOSTN=0.934, URIBL_BLOCKED=0.001] autolearn=disabled

On new server:

    score=3.204 tagged_above=-999 required=3.4
    tests=[ARCHIVE_PASSWORD=5, BAYES_00=-1.9, HTML_MESSAGE=0.001,
    MIME_HTML_ONLY=0.1, NO_FM_NAME_IP_HOSTN=0.001, SPF_NONE=0.001,
    URIBL_BLOCKED=0.001] autolearn=disabled

All configs have been migrated unchanged from the original to the new 
server.

Please advise on what I may be doing wrong in setting up the migrated db!

Why do the two servers produce so different results in terms of BAYES 
filtering (BAYES_999=2.7, BAYES_99=3.7 vs BAYES_00=-1.9)?

Thanks in advance.

Cheers,
Nick