[exim] Envelope-To after Alias Redirect

Hi,

When using a redirect in Exim for an Alias, the Envelope-To is re-
written for future lookups.

So bob@??? -> james@???

Then does future lookups for james@??? when checking things
like spam if a user should be checked for spam.. $local_part and
$domain for example.

When writing the Message to the Maildir it also writes Envelope-To: as
the redirected Email Address and not the Email Address which was
originally sent to..

How can I make it write the original email address which was entered
in the RCPT To and not the address redirected to?

Jonathan