[exim] not rewrite the To: Address

If the To: name in the headers is for example "Test group" with no valid
email address but the envelope to addresss is a valid email address, how can
we prevent exim adding a @ sign after the To name
eg "Test Group"@. It used to add the @ sign and then the primary_hostname
but we have taken that out with :
qualify_recipient =
qualify_domain =

and a rewrite rule:
begin rewrite
*                   *     tQq

but the @ sign is still there. How do we get rid of it...

Below is our conf file:

primary_hostname = test.server.com
qualify_recipient =
qualify_domain =
local_interfaces = 127.0.0.1
domainlist local_domains =
domainlist relay_to_domains =
hostlist relay_from_hosts = 127.0.0.1
acl_smtp_rcpt = acl_check_rcpt
never_users = root
rfc1413_hosts = *
rfc1413_query_timeout = 0s
ignore_bounce_errors_after = 8h
message_size_limit=256M
timeout_frozen_after = 7d
split_spool_directory
bounce_return_message = false
log_selector = +sender_on_delivery +smtp_confirmation

begin acl

acl_check_rcpt:
  accept  hosts = :
  deny    domains       = +local_domains
          local_parts   = ^[.] : ^.*[@%!/|]
  deny    domains       = !+local_domains
          local_parts   = ^[./|] : ^.*[@%!] : ^.*/\\.\\./
  accept  hosts         = +relay_from_hosts
  deny    message       = relay not permitted

begin routers

#Smarthost routing
smart_routing:
driver = manualroute
transport = remote_smtp
route_data = ${lookup
{$sender_address_domain}lsearch*{/var/rocketseed/system/smartrouting.mta}}

dnslookup:
driver = dnslookup
domains = ! +local_domains
transport = remote_smtp
ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8
no_more

begin transports

remote_smtp:
driver = smtp
# transport_filter = /var/tmp/toremove.pl

begin retry
*                      *           F,2h,15m; G,16h,1h,1.5; F,4d,6h

begin rewrite
*                   *     tQq