hosts files
Sendmail.cf has /etc/mail/service.switch
as the default location for this file.If you use a shared aliases file, the user specified as postmaster in /etc/mail/aliases must be permitted to all security labels supported for sendmail. If you need to have different aliases, you must provide a separate aliases file for each security label. The user specified as postmaster in each security label-specific aliases file must be permitted to that security label.