[exim] Adding a header at router level

Hi,

I wanted to add a header for all the forwarded mails from server. The
router I am using for this purpose is:


add_header_for_forwarders:
driver = redirect
require_files = "+/etc/valiases/$domain"
data = ${lookup{$local_part@$domain}lsearch{/etc/valiases/$domain}}
condition = ${lookup{$local_part@$domain}lsearch{/etc/valiases/$domain}
{yes}{no}}
headers_add = X-MyHeader: ${perl{getdomainowner}{$domain}}
pipe_transport = ${if
forall{/bin/cagefs_enter:/usr/sbin/cagefsctl}{exists{$item}}{cagefs_virtual_address_pipe}{${if
match{${extract{6}{:}{${lookup
passwd{${lookup{$domain}lsearch*{/etc/userdomains}{$value}}}{$value}}}}}{\N(jail|no)shell\N}{jailed_virtual_address_pipe}{virtual_address_pipe}}}}
unseen


But for some reason the header addition isn't happening.

Also, if the header already exist will header_add again add the header or
will it edit the existing headers?
--
Regards,
Soumya