A common cause of this problem is that the NS records for the website were created, but 'A' records for that domain name were not. You will need to fill out the "Mail Exchanger (MX) records" section and the "Address 'A' Records" section as well as the "Name Server (NS) records section for your website at the Universal Pipe DNS Management tool (http://dns3.speedingbits.com).

The set of name server entries to use in the Universal Pipe DNS Management tool and at your registrar should be identical. Use either:

dns3.speedingbits.com
dns4.speedingbits.com

or

dns1.simplywebhosting.net
dns2.simplywebhosting.net