[exim] Spamd Timeout

Hi,

My Exim (version 4.69) sometimes generates "spam acl condition: error
reading from spamd socket: Connection timed out" messages in the mainlog.
When I match this error with spamassassin's log I read very long scan
times (> 120s).

The server is not really heavily loaded.

Before considering removing some scan options in spamassassin, I'd
rather like to raise exim's timeout to spamd's answer.

I could not find any parameter to adjust this timeout and all the
messages I read about this problem offer to raise the --max-children
parameter of spamassassin as a solution. I'm pretty sure this is not the
solution here.

Is this spamd timeout hard coded ? Is there a workaround ?

Thank you very much