I need to send email using smtp on port 587 on a Red Hat Linux ES 3 system.

I have a customer that I inherited running Red Hat Linux ES 3 that wants to send email from the Linux side.  
I need to be able to send email using port 587.

cat /etc/redhat-release
Red Hat Enterprise Linux ES release 3 (Taroon)

The Windows support person says smtp must use port 587.

SMTP: smtp.emailarray.com  Port: 587
Login: info@computerohio.com

/etc/services
smtp            25/tcp          mail
smtp            25/udp          mail
submission      587/tcp         msa             # mail message submission
submission      587/udp         msa             # mail message submission

Since 587 is used by submission can smtp also be changed to 587 in the /etc/services file?

netstat -tanp | grep send | grep LISTEN
tcp        0      0 127.0.0.1:25            0.0.0.0:*    LISTEN      483/sendmail: acce

The Windows support person also says the following:
The Windows server is running DNS, so you may want to change the DNS servers to:
10.10.10.176
8.8.8.8
It should resolve "smtp.emailarray.com" to 69.28.212.198.

cat /etc/resolv.conf
nameserver 10.10.10.1
nameserver 68.10.16.25
nameserver 10.10.10.176
nameserver 8.8.8.8
search appemc


cat /etc/sysconfig/networking/devices
# Intel Corp.|82540EM Gigabit Ethernet Controller
DEVICE=eth0
BOOTPROTO=none
BROADCAST=10.10.10.255
HWADDR=00:c0:9f:27:7b:8f
IPADDR=10.10.10.100
NETMASK=255.255.255.0
NETWORK=10.10.10.0
ONBOOT=yes
TYPE=Ethernet
USERCTL=no
PEERDNS=yes
GATEWAY=10.10.10.1


cat /etc/sysconfig/networking/profiles/default/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1       localhost.localdomain   localhost       appemc
10.10.10.100    emc2
10.10.10.175    emcws
10.10.10.176    emcws2
10.10.10.93     upspc
10.10.11.2      dhk61353
#65.39.216.39   smtp.emailarray.com

cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=appemc

cat /etc/sysconfig/networking/profiles/default/network
HOSTNAME=appemc


grep DS /etc/mail/sendmail.cf
DS
# Return-Receipt-To: header implies DSN request
# DHParameters (only required if DSA/DH is used)

grep SMART sendmail.mc
dnl define(`SMART_HOST',`smtp.your.provider')

grep DAEMON sendmail.mc
DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl
dnl DAEMON_OPTIONS(`Port=submission, Name=MSA, M=Ea')dnl
dnl DAEMON_OPTIONS(`Port=smtps, Name=TLSMTA, M=s')dnl
dnl DAEMON_OPTIONS(`port=smtp,Addr=::1, Name=MTA-v6, Family=inet6')dnl

Below is an entry from /var/log/maillog:
Nov  8 22:17:11 localhost sendmail[18475]: vA93GY7L018471: to=<dkaibjr@verizon.n
et>, ctladdr=<root@localhost.localdomain> (0/0), delay=00:00:29, xdelay=00:00:29
, mailer=esmtp, pri=33202, relay=mailin-01.mx.aol.com. [64.12.88.132], dsn=5.0.0
, stat=Service unavailable

I did not install the Red Hat Linux on this system and not local to the equipment.
I do not have access to the console so everything I do needs to be from the command line.

One issue found from the original install was that the hostname was set as
HOSTNAME=localhost.localdomain

Thank you for any help you can provide.

Dan