Node:Controlling Header Display, Next:Displaying Information, Previous:Changing mailbox/directory, Up:Reading Mail
To control which headers in the message should be displayed, mail
keeps two lists: a retained header list and an ignored
header list. If retained header list is not empty, only the
header fields listed in it are displayed when printing the message.
Otherwise, if ignored header list is not empty, only the headers
not listed in this list are displayed. The uppercase variants
of message-displaying commands can be used to print all the headers.
The following commands modify and display the contents of both lists.
discard [header-field-list]
di [header-field-list]
ignore [header-field-list]
ig [header-field-list]
retain [header-field-list]
ret [header-field-list]