auth_relay:
    driver = smtp
    port = 25
    hosts_require_auth = $host_address
    hosts_require_tls = $host_address
    headers_add = "${if def:authenticated_id{X-Authenticated-Id: ${authenticated_id}}}"
    interface = <; ${if exists{/etc/virtual/domainips}{${lookup{$sender_address_domain}lsearch*{/etc/virtual/domainips}}}}
    helo_data = ${if exists{/etc/virtual/helo_data}{${lookup{$sending_ip_address}iplsearch{/etc/virtual/helo_data}{$value}{$primary_hostname}}}{$primary_hostname}}
    hosts_try_chunking =
    hosts_try_fastopen =
.include_if_exists /etc/exim.dkim.conf