OTRS is able to send out emails via Sendmail (e. g. Sendmail, Postfix, Qmail or Exim). The default configuration to use Sendmail should work out of the box.
There are the following config options for Kernel/Config.pm:
# SendmailModule # (Where is sendmail located and some options. # See 'man sendmail' for details.) $Self->{'SendmailModule'} = 'Kernel::System::Email::Sendmail'; $Self->{'SendmailModule::CMD'} = '/usr/sbin/sendmail -t -i -f '; |