[Exim] SpamAssassin doesn't like Exim's MessageID

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Hi,
I'm using exim 4.30 with exiscan and SpamAssassin (SA).
I've noticted that all the mail that is leaving our mail server is tagged by
one of SA rules as if it has a bad message ID.

It generates spamassassin report lines like:
0.3 RATWR7a_MESSID         Message-ID has ratware pattern (12hex$8hex$8hex@)

The rules file is the popular "ratware.cf" (not part of the core SA rules)
and the rule is defined as:

header RATWR7a_MESSID Message-ID =~ /<[a-z0-9]{12}(\$[a-z0-9]{8}){2}\@/

Is this rule is correct, the message ID generated by exim is similar to some
common patterns found with spammers.
Should the rule be modified or should exim be modified to generate a
different message ID string?

Thanks,
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Ilan Aisic

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