Despite X-Spam-Status Scores above Required Spam isn't sorted out of mbox - procmail

Question

I'm trying to run my mbox file through spamassassin with:
formail -s procmail ~/procmail.rc < mbox
Despite what I think looks like a proper procmail rc file & an ok spamassassin local.cf the mail that gets scored higher than my 'required' is not being filtered into my probably-spam folder.
Any spamassassin experts who can help?
This is on Ubuntu 16.04LTS
From my email header:
X-Spam-Status: No, score=-5.0 required=3.0 tests=RCVD_IN_DNSWL_HI,SPF_PASS,
T_RP_MATCHES_RCVD autolearn=unavailable autolearn_force=no version=3.4.1
My spamassassin local.cf:
rewrite_header Subject *****SPAM*****
report_safe 0
required_score 3.0
use_bayes 1
bayes_auto_learn 1
normalize_charset 1
ifplugin Mail::SpamAssassin::Plugin::Shortcircuit
shortcircuit BAYES_99 spam
shortcircuit BAYES_00 ham
endif # Mail::SpamAssassin::Plugin::Shortcircuit
My procmailrc:
:0fw: spamassassin.lock
* < 256000
| spamassassin
:0:
* ^X-Spam-Level: \*\*\*
almost-certainly-spam
:0:
* ^X-Spam-Status: Yes
probably-spam
# Work around procmail bug: any output on stderr will cause the "F" in
"From"
# to be dropped. This will re-add it.
:0
* ^^rom[ ]
{
LOG="*** Dropped F off From_ header! Fixing up. "
:0 fhw
| sed -e '1s/^/F/'
}

Answer 1

I cannot see any apparent mistakes in your spamassassin local.cf and procmailrc. But the example email header clearly says that it is no spam. The score is not higher, it is -5 which is lower than 3. Hence it says "X-Spam-Status: No".
Note that the procmail workaround should not be needed anymore. However, you might want to use -f -, i.e.
formail -s procmail -f - ~/procmail.rc < mbox