Here is the output of:
sudo exim4 -d -bt root
Exim version 4.76 uid=0 gid=0 pid=25417 D=fbb95cfd
Berkeley DB: Berkeley DB 5.1.25: (January 28, 2011)
Support for: crypteq iconv() IPv6 GnuTLS move_frozen_messages DKIM
Lookups (built-in): lsearch wildlsearch nwildlsearch iplsearch cdb dbm dbmnz
dns
db dsearch nis nis0 passwd
Authenticators: cram_md5 plaintext
Routers: accept dnslookup ipliteral manualroute queryprogram redirect
Transports: appendfile/maildir/mailstore autoreply lmtp pipe smtp
Fixed never_users: 0
Size of off_t: 8
Compiler: GCC [4.6.1]
Library version: GnuTLS: Compile: 2.10.5
Runtime: 2.10.5
Library version: PCRE: Compile: 8.12
Runtime: 8.12 2011-01-15
Total 12 lookups
WHITELIST_D_MACROS: "OUTGOING"
TRUSTED_CONFIG_LIST: "/etc/exim4/trusted_configs"
changed uid/gid: forcing real = effective
uid=0 gid=0 pid=25417
auxiliary group list: <none>
seeking password data for user "uucp": cache not available
getpwnam() succeeded uid=10 gid=10
configuration file is /var/lib/exim4/config.autogenerated
log selectors = 00000ffc 00612001
trusted user
admin user
seeking password data for user "mail": cache not available
getpwnam() succeeded uid=8 gid=8
user name "root" extracted from gecos field "root"
originator: uid=0 gid=0 login=root name=root
sender address = root@???
Address testing: uid=0 gid=127 euid=0 egid=127
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Testing root@???
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Considering root@???
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
routing root@???
--------> hubbed_hosts router <--------
local_part=root domain=mydomain.com
checking domains
expansion of "${if
exists{/etc/exim4/hubbed_hosts}{partial-lsearch;/etc/exim4/hu
bbed_hosts}fail}" forced failure: assume not in this list
hubbed_hosts router skipped: domains mismatch
--------> smarthost router <--------
local_part=root domain=mydomain.com
checking domains
mydomain.com in "@:localhost:ubuntu"? no (end of list)
mydomain.com in "! +local_domains"? yes (end of list)
R: smarthost for root@???
calling smarthost router
smarthost router called for root@???
domain = mydomain.com
DELETED from here – server details.