[Pkg-exim4-users] Why the DKIM-Signature header isn't created when a mail is relayed to the smarthost ?

[Andreas Metzler]

Satoru Otsubo <trnsnt at otip.jp> wrote:
>> Hello,
>> the shipped configuration does not support DKIM signing on the
>> remote_smtp_smarthost transport. - You wwould need to modify the
>> transport.

> Does this mean that I would need to rebuild Exim4 ?
> Or does this mean that I would need to merely change
> exim4.conf.template (in case of dc_use_split_config='false') ?

Hello,
No rebuild would be necessary, just changing the configuration.

>> I doubt whether the added DKIM signature will have any significant
>> effect on this.

> Does this mean that even if the DKIM signature is added, mails via
> smarthost would be interpreted as spam mail ?  If so, why ?

A DKIM signature is not a strong sign of not being spam. It just says
"this mail passed through this server". There is good reason why
spamassassin only scores very weakly on DKIM.
https://github.com/apache/spamassassin/blob/trunk/rules/50_scores.cf

cu andreas
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