About Header Check Depth

By default, ORF considers the host which from your server (or Intermediate Hosts) received the email as the sender at the On Arrival filtering point: this host is identified by analyzing the header. ORF 4.4 and earlier versions could be configured to check more than one host after your server / Intermediate Hosts against online DNS Blacklists by setting this default header check depth value higher than one.

Reasons for removing this setting from the user interface

As many ORF users misused this feature (instead of compiling a proper Intermediate Host list, many people set the Header check depth to unlimited, which led to many problems and false positives), we decided to remove this from the GUI of ORF version 5. When upgrading to ORF 5 from a previous version with header check depth set higher than 1 or unlimited, this setting is preserved in the main configuration file called orfent.ini as follows:

As the GUI can no longer be used to modify these values, the configuration file should be edited manually if any values should be changed. We recommend setting these values to:

If properly configured, you will never need to set this value higher than one, but to keep ORF backward-compatible, this setting can still be modified by editing the configuration file of ORF 5 and later versions.