Blocked BAD-HEADER-0 {RejectedInbound,Quarantined

[taft at unclet.net]

See in-line answers.

On 8/27/22 2:36 AM, Damian wrote:
>> I've got a few remote senders whose messages my server is rejecting 
>> and putting this in syslog: Blocked BAD-HEADER-0 
>> {RejectedInbound,Quarantined}
>
> This is strange, I cannot find a code path which sets CC_BADH without 
> setting the minor > 0.
I think I'm using a version packaged for RHEL (2.12.0-10.el7), so it's 
probably old, but other than that, I don't think I've done anything that 
should change code paths.
>
>> How do I determine what exactly is wrong with the header that the 
>> remote server is sending?
>
> What is your log_level and do you see "check_header: " log lines?
>
$log_level = 1;

I don't see check_header in the logs.

What should I set it to?

>> If I can't get the remote site to fix their stuff, is there a way to 
>> bypass the header check for their domains only?
>
> If they DKIM-sign their mails, you can use author_to_policy_bank_maps 
> and disable header checks inside such policy_bank.

And if they don't, what's suggested?

Is there a way to configure the system to reject messages with bad 
headers, but to do the rejection with a temporary, rather than a 
permanent code, so that the the remote system should attempt the sending 
again later?

-- 
Todd D. Taft
taft at unclet.net