Mailscanner not tagging spam

[Paul Welsh]

Hi
I'm using version 4.64.3 of MailScanner with Spamassassin 3.2.3 with Exim.
At around 4am yesterday MailScanner stopped detecting spam.  Looking through
the maillog, the "Found x spam messages" stopped at around 4am.  I restarted
MailScanner and Exim and this seemed to fix it.

However, today although MailScanner says it is detecting spam, it's still
coming through.  If I test some of the messages that are getting through
using SpamAssassin in debug mode, the messages are clearly high scoring
spam.  I've received no messages with a modified subject line, ie, with the
{Spam?} prefix and the Internet headers show the messages have not been
classified as spam by MailScanner.  I've set "Always Include SpamAssassin
Report" to yes from no so I can get a bit more detail and I'm waiting for
MailScanner to do one of its periodic restarts.
 
Any ideas what could be going wrong or what I can do to debug the problem? 
The server in question has been up for 417 days, do you think a reboot may
solve the issue?

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