[exim] Header remove before spam check or parse content in r…

Hello

Since two weeks few contacts send us mail with header X-Spam-Flag
already set (to "NO")

So after spamassassin check we have 1 or 2 occurrence of X-Spam-Flag
and us router match them like spam at each time.

We try a lot of configuration but we found no solution to remove
X-Spam-Flag before ACL check or to check X-Spam-Flag value in router
condition.

Does anyone can help us ?

## Router sample
user_spam:
  debug_print           = "R: SPAM for $local_part@$domain"
  cannot_route_message  = no such user
  driver                = accept
  condition             = {def:h_X-Spam-Flag:} }}
...
##

Thanks for any help

Florent