I can not force exim4 mailname, please help

[Cameron James]

Hi there i can not seem to force exim4 to use /etc/mailname

root at ip-172-31-16-131:/etc# uname -a
Linux ip-172-31-16-131 3.2.0-4-amd64 #1 SMP Debian 3.2.65-1+deb7u1 
x86_64 GNU/Linux

root at ip-172-31-16-131:/etc# exim4 --version
Exim version 4.80 #3 built 24-Jul-2014 03:28:10
Copyright (c) University of Cambridge, 1995 - 2012
(c) The Exim Maintainers and contributors in ACKNOWLEDGMENTS file, 2007 
- 2012
Berkeley DB: Berkeley DB 5.1.29: (October 25, 2011)
Support for: crypteq iconv() IPv6 GnuTLS move_frozen_messages DKIM
Lookups (built-in): lsearch wildlsearch nwildlsearch iplsearch cdb dbm 
dbmjz dbmnz dnsdb 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
Configuration file is /var/lib/exim4/config.autogenerated

Im sorry if ive posted this to the wrong place im at my witts end, ive 
tried for 2 hours and can not force exim4 to use the /etc/mailname any 
help would be really appreciated!

Kind Regards,
Cameron James