Type: path
Default: "builtin"
This variable specifies which pager you would like to use to view messages. builtin means to use the builtin pager, otherwise this variable should specify the pathname of the external pager you would like to use.
Using an external pager may have some disadvantages: Additional keystrokes are necessary because you can't call mutt functions directly from the pager, and screen resizes cause lines longer than the screen width to be badly formatted in the help menu.