[exim] Sending emails through Spam Assassin

Hello all,

I am trying to send emails through Spam Assassin to warn and add headers
so people can move emails to spam folders using rules or filters

the config I have pinched uses the following:

warn    spam       = nobody:true
           add_header = X-Spam_score: $spam_score\n\

Why is it 'nobody'?

Cheers


Simon