The dotforward program is a compatibility module that reads forwarding instructions in $HOME/.forward. dotforward is used for compatibility with sendmail or other mail servers that use the $HOME/.forward file. The dotforward program is intended to be executed from a dot-courier(5) delivery instruction file. The system administrator can add it to the default set of delivery instructions, thus unilaterally implementing $HOME/.forward systemwide. To read forwarding instructions from $HOME/.forward, put “|| dotforward” on the first line of $HOME/.courier*. “|| dotforward” can also be added to the DEFAULTDELIVERY setting in the courierd configuration file. In both cases it must be followed by a newline, and the remaining delivery instructions, which will be used if $HOME/.forward does not exist.

dot-forward - couerie.mta

勘を便りに適当に要約すると、sendmailとかで使ってた.forwardを使えるようにするには、$HOMEで指定されたディレクトリに、.courier (-*)的なファイルを作って、そこに下記のとおり書きます。

|| dotforward