debian 8 + ISPCONFIG OVH VPS
https://www.howtoforge.com/tutorial/perfect-server-debian-8-jessie-apache-bind-dovecot-ispconfig-3/
no se ha instalado SQRMAIL de este tutorial
SPF/DKIM:
SPF Wizard:
http://www.spfwizard.net/es/
DKIM Help:
http://eltallerdelbit.com/configuracion-de-registros-spf-y-dkim/
roundcube webmail:
https://www.howtoforge.com/tutorial/roundcube-installation-on-debian-8-jessie/