DirectMX will reject messages that come from a domain that has SPF configured, and the email does...DNS Settings - MX & SPF records
DNS MX Records Configuring your DNS records is a critical step in putting your DirectMX service...IP & Firewall Settings
Firewall Information DirectMX connects directly to your mail server for a variety of reasons....Outbound Smarthost setup - Exchange 2003
Included below are the instructions to configure a smarthost on Exchange 2003. Please note these...Outbound Smarthost setup - Exchange 2007 & 2010
Included below are the instructions to configure a smarthost on Exchange 2007 and 2010. Please...SPF, Whitelists and You
Are you getting an error that a whitelisted sender is ignored due to SPF fail, maybe like this?...