An SPF record is used to to show other mail servers which servers or IP address are used to send email for a domain. Mail server are then able to reject emails that are sent from other locations as possible spam.
As part of its security to ensure that only authorised emails can send messages Echo For Email looks for an SPF record on your domain's DNS.
As such we recommend that you ask your IT team to create an SPF record for your domain. The following link shows how to go about creating the content of your SPF record which can then be added to your DNS:
http://old.openspf.org/wizard.html
If you use an email provider then the following URL's may be of assistance:
Google on SPF records: http://www.google.com/support/a/bin/answer.py?answer=178723
Hotmail: http://explore.live.com/domains/enter-a-sender-id-in-dns?mkt=en-us
MessageLabs (now part of Symantec): http://help.symanteccloud.com/Symhelp/Home.aspx/Default?localeId=EN_US&topicId=v51748642_v53091618&prodId=MLKBAS
Rackspace: http://www.rackspace.com/apps/support/portal/1212
