[Kolab-devel] [issue2244] SpamAssassin uses DNS blacklists

[Thomas Arendsen Hein]

New submission from Thomas Arendsen Hein <thomas at intevation.de>:

Different DNSBLs have different policies, which have to be evaluated before
using them, e.g. some are listing hosts which are also TOR nodes. And even
worse, these policies sometimes change.

DNSBLs sometimes have technical or organisational problems or will simply be
shut down which may result in all mail being flagged as spam. Yes, I have seen
this in the wild!

Some DNSBLs are not free for use for anyone, e.g. only allow up to X mailboxes
or don't allow forwarding mails (e.g. hosting mailinglists). This also can
change over time.


For Kolab Server 2.1 this problem was worked around by using a custom local.cf
to disable all DNSBLs, for 2.2 there are various possibilities:

- disable all network checks by default (can this be done in the amavisd template?)
- add a kolabd template for local.cf (might be good anyway)
- ask SpamAssassin upstream for recommendations

In any case using DNS blacklists should have to be enabled by the admin
intentionally, not by default.

----------
assignedto: thomas
messages: 12772
nosy: bernhard, martin, steffen, thomas, wilde, wrobel
priority: urgent
status: unread
title: SpamAssassin uses DNS blacklists
topic: release, server
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