[Mimedefang] SA autolearn, missing bayes_journal file

[Marcus Schopen]

Hi,

I'm wondering about missing bayes_journal file using mimedefang 2.78 and
Spamassassin 3.4.1. On another instance with (what I see) same
configuration this file is created. 
 Because upgrading from a SA version < 3.4.0 I wiped its database
"sa-learn -dbpath /var/spool/MIMEDefang/.spamassassin --clear" as
considered in SA upgrade path. Anything misconfigured here?

------
sa-mimedefang.cf:
use_bayes 1
bayes_auto_learn 1
------

------
$ /usr/bin/sa-learn --dbpath /var/spool/MIMEDefang/.spamassassin --dump
magic
0.000          0          3          0  non-token data: bayes db version
0.000          0         57          0  non-token data: nspam
0.000          0       5484          0  non-token data: nham
0.000          0     162297          0  non-token data: ntokens
0.000          0 1475388662          0  non-token data: oldest atime
0.000          0 1475574294          0  non-token data: newest atime
0.000          0 1475572767          0  non-token data: last journal
sync atime
0.000          0 1475561433          0  non-token data: last expiry
atime
0.000          0     172800          0  non-token data: last expire
atime delta
0.000          0      35010          0  non-token data: last expire
reduction count
------

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ls -al /var/spool/MIMEDefang/.spamassassin
insgesamt 4708
drwx------   2 defang defang    4096 Okt  4 11:19 .
drwxr-x--- 437 defang defang   65536 Okt  4 10:53 ..
-rw-------   1 defang defang    2490 Okt  4 11:47 bayes.mutex
-rw-------   1 defang defang  655360 Okt  4 11:47 bayes_seen
-rw-------   1 defang defang 5406720 Okt  4 11:47 bayes_toks
------

Btw: what's are good values for bayes_auto_learn_threshold_nonspam and
bayes_auto_learn_threshold_spam?

Ciao
Marcus