You will need to contact your DNS hosting company and ask them to change your MX records and also add a CNAME.
Your DNS hosting company is usually your Registrar; where you purchased your domain, or the company that hosts your web site. If you are not aware of who hosts your DNS zone file, we recommend contacting the company hosting your web site.
Changing Your MX Records
You will need to change your MX records to reflect the following values:
mx01.securembox.com - 10
mx02.securembox.com - 20
mx03.securembox.com - 30
mx04.securembox.com - 40
Please ensure that ALL domain aliases are adjusted to reflect the updated settings.
Changing Your SPF Record
yourdomain.com IN TXT "v=spf1 include:_spf.securembox.com ~all"
For more information on SPF record benefits please click on the link below.
In order for Exchange 2013 to function correctly, you will need to create a CNAME in your DNS records as indicated below.
autodiscover CNAME redir.na02.secureowaonline.com