[CentOS] dumb sendmail question -- how to get outbound messages to use "example.com" instead of hostname?

[Brent L. Bates]

     On our servers here are some sendmail.mc lines referring to our domain.
 May be they will help.  These are from our main server:

define(`confDOMAIN_NAME',vigyan.com)dnl
CLIENT_OPTIONS(`Family=inet,Addr=vigyan.com')dnl
define(`SMART_HOST',`vigyan.com')dnl
FEATURE(`smart_host_domain',`vigyan.com ')dnl

These are from our slave servers:

CLIENT_OPTIONS(`Family=inet,Addr=slave.vigyan.com')dnl
MASQUERADE_AS(vigyan.com)dnl
MASQUERADE_DOMAIN(vigyan.com)dnl
FEATURE(`allmasquerade')dnl
FEATURE(`masquerade_entire_domain')dnl
FEATURE(`masquerade_envelope')dnl
define(`SMART_HOST',`slave.vigyan.com')dnl
FEATURE(`smart_host_domain',`vigyan.com ')dnl

     Good luck.