[exim] Block Authenticated Senders Listed in File

I want to block certain authenticated senders. Not the from address
but the username they do smtp authentication with.

I tried this:

deny authenticated = *
        message = $authenticated_id suspended due to abuse
        #condition = ${if eq{$authenticated_id}{ttest@???} }
       condition = ${if eq{$authenticated_id}{lsearch;/var/bad_senders}

It seems to work when I input a single email address but I want to
block all the email addresses listed in the file bad_senders. What am
I doing wrong?