Richweb mail servers are internet best practices compliant and we use SPF records as well DKIM (Domain Keys Signed Messages) for Referral Trak email alerts. These best practices are required and used by the major email providers (yahoo.com. MSN, gmail, etc). Some organizations have needed to manually whitelist us in the past years as their systems may not be recent enough to take advantage of some of the technology we use. Here is the info you will need to do that: All referral trak emails will come from our DIM message signing relay: 208.73.137.16 vs52.richweb.com. Make sure this IP address and or DNS name is whitelisted, and make sure donotreply@referraltrak.com is whitelisted as that is the envelope from address that email alerts will originate from. The following domains may need to be whitelisted so that all messages get through from Referral Trak as well as Richweb support team members: 1. referraltrak.com 2. richweb.com