[Exim] wacky idea with exiscan and SpamAssassin

[sent to exim-users as I don't think it's a legal config]

Hi,

I'd quite like to do something like the following (DATA ACL; requires the
exiscan-acl patch):

  warn    !authenticated = *
          condition = ${if <{$message_size}{80k}{1}{0}}
          spam = nobody:true
          log_message = spam score: $spam_score
          message = X-Spam-Report: $spam_report
          condition = ${if >{$spam_score_int}{30}{1}{0}}
          delay = {$spam_score_int}s

It's the last line which is jazzy. It's completely untested, but the idea
is that before sending "250 OK id=.." a delay proportional to the
SpamAssassin score occurs. A score of 59 would be within the minimum
RFC2821-suggested timeout (at this point in the SMTP conversation),
assuming that Exim takes less than 10 seconds to process it! Nevertheless,
I should probably include traps for this, and for negative scores.

I don't think the Exim spec (37.11; 6.11) states whether "delay =" values
are expanded or not. If they're not then of course the above is illegal.

Matt