Header Option File Location

For destination channel based header trimming to be applied upon message enqueue after normal header processing, the MTA looks in the config directory (msg_svr_base/config) for header options files with names of the form channel_headers.opt, where channel is the name of the channel with which the header option file is associated. The headertrim keyword must be specified on the channel to enable the use of such a header option file.

For source channel based header trimming to be applied upon message enqueue before normal header processing, the MTA looks in the config directory (msg_svr_base/config) for header options files with names of the form channel_read_headers.opt, where channel is the name of the channel with which the header option file is associated. The headerread keyword must be specified on the channel to enable the use of such a header option file.

Header option files should be world readable.