If you have signed up for Business Email but will configuring your own DNS in an external system, below are the DNS records you will need.
Your MX record should have a priority of 0 and be set to the following (replacing the "example.com" portion with your own domain name):
mx.example.com.cust.b.hostedemail.com
You will also want an SPF record configured. An SPF record is a TXT type record, and should be set with this content:
v=spf1 include:_spf.hostedemail.com ~all
If you have other mail services as well, you may just need to insert the "include:_spf.hostedemail.com" portion into your existing SPF record.
For best deliverability you should also have a DKIM record. DKIM records are unique and we will provide your unique DKIM details when we get your account set up.