Instant Capacity on Demand (iCOD) User's Guide for versions B.05.x

Understanding iCOD Requirements
E-Mail Requirements
Chapter 226
Overview of E-mail Routing Across the Internet
When sendmail is invoked, by the iCOD software, to send e-mail to HP,
sendmail determines where it should initially send the e-mail (the first
hop). Mail often goes through multiple systems (hops) before it reaches
the final destination. To determine the first hop for the e-mail, sendmail
uses one of the following:
• The e-mail is routed to a mail relay host if it is configured in the
/etc/mail/sendmail.cf configuration file. This is the easiest
implementation and can be done with just a one line change (DS) to
the default /etc/mail/sendmail.cf file.
Note that the relay host must be configured to properly route
(forward) the mail to the final destination.
• DNS MX records - this method requires that the iCOD system be in
an environment (network) where DNS (Domain Name Server) is
operating and properly configured. sendmail on the system queries a
DNS server for the name of the mail server to forward the e-mail to
(for the first hop) in order for the e-mail to reach the final destination
(hp.com).
In all cases, the following requirements must be met:
• HP’s mail servers receiving mail expect the host (the mail server in
the last hop before reaching HP) to be properly registered in DNS.
Otherwise the HP mail server rejects or “bounces” the e-mail.
• The 'From' field (e-mail address), in the e-mail message, must be
known by the receiving mail server (that is, the hostname is
registered in DNS and advertised on the internet). Otherwise the
receiving mail server at HP rejects the mail. This field in the e-mail
can be configured with a simple one line modification (DM) to the
/etc/mail/sendmail.cf file.
In some DNS environments no changes to the default
/etc/mail/sendmail.cf file may be needed to properly route e-mail
from the iCOD system to HP.