Indeed, postfix uses the system logging daemon (which is why mail.log
was not being updated with no rsyslog).  You can customize it in
/etc/rsyslog.conf (or /etc/rsyslog.d/postfix.conf).
I've got a bit of a custom setup.  The default configuration (if I
recall correctly) sends ALL mail.* log messages to both syslog and
mail.log, which seemed unnecessary (to me).  Also mail.log contained ALL
mail log messages, including the ones that were sent to mail.warn and
mail.err.  To me, the less duplication, the better.  If you do make
changes, be sure to restart the rsyslog service.

# First some standard log files.  Log by facility.
#
*.*;auth,authpriv.none;mail.none        -/var/log/syslog
...
# Logging for the mail system.  Split it up so that
# it is easy to write scripts to parse these files.
#
mail.err /var/log/mail.err
& stop
mail.warn -/var/log/mail.warn
& stop
mail.* -/var/log/mail.log
#mail.info            -/var/log/mail.info
#mail.warn            -/var/log/mail.warn
#mail.err            /var/log/mail.err



Hendrik Boom wrote:
> On Wed, Jul 28, 2021 at 12:06:46PM +0200, Antony Stone wrote:
>> On Tuesday 27 July 2021 at 18:27:47, Hendrik Boom wrote:
>>
>>> And, while I'm asking anyway, why no /var/log/mail* since 2013 either?
> Problem has been found: no system logging demon.
>> /var/log/mail* would be created by sendmail (and perhaps others), but the
>> default for Debian (and therefore Devuan) is Exim, which logs to
>> /var/log/exim4/*
>>
>> So, I'm wondering whether either:
>>
>> a) you were previously using sendmail, which generated the log files you see,
>> and then changed (perhaps unknowingly) to Exim, which logs somewhere else
> I'm using postfix, which it appears uses the system loggin demon for its log.
>
>> or
>>
>> b) this disk had content from some previous system which last got used in May
>> 2013, and then some subsequent installation or upgrade, without wiping the
>> disk first, has resulted in the system you now have, which isn't logging to
>> those same files?
> That could be. Perhaps an upgrade in 2013 removed the logging demon
> (which I just now installed again.)
>
> -- hendrik
>
>> What are the ownership and permissions on:
>>
>> /var
>> /var/log ?
>>
>>
>> Antony.
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