[exim] $message_id expansion variable

Hi folks,

When is the $message_id expansion variable set during the life of a message?
I'm trying to setup a way to track a message through the various ACLs that I
have setup and I'm curious if $message_id can be used during the 'early' ACLs
like acl_smtp_connect, acl_smtp_helo, etc.

If this is in the docs, can someone point me to the appropriate section? I
have not been able to find it.

Thanks,
mikeS

-- 
Michael Sprague  | mfs@???
Partner          | System and Network Engineering (SaNE), LLC
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