"Phishing" is the fraudulent practice of sending emails purporting to be from reputable companies in order to induce individuals to reveal personal information, such as passwords and credit card numbers. As more and more phishing scams are being circulated via email, email providers are becoming that much more aggressive in their efforts to block it.
This is a good thing, but it has also resulted in a higher percentage of legitimate email being mis-identified as forged and never making it to it's intended recipient. If you have had customers tell you that they're not receiving their ASAP emails, this may be why.
To address this ASAP is in the process of moving all of our email processing over to a service called Mandrill. Mandrill supports two email authentication systems know as DKIM (DomainKeys Identified Email) and SPF (Sender Policy Framework) that allow companies to verify that the emails they're sending are valid, which increases the odds of those emails being delivered.
However, in order to enable these authentication techniques you must first make a change to the account that hosts your domain name. The instructions for doing so are below. After you have completed the following steps you will then need to contact ASAP at email@example.com so we can verify that everything was done correctly. At that point we can switch your email over to Mandrill.
How to implement DKIM and SPF
DKIM and SPF need to be added to the server that hosts your domain name (godaddy, webgator, etc). Your host's customer support team can help you with this, or if you have a technical support person at your organization they can help as well. If they're unable to help we can set it up for you provided you provide us with access to your host account (please contact our team at firstname.lastname@example.org and include DKIM in the email somewhere).