have not yet found syntax for pipe in a .forward. Can you help me with that?

When ever I leave the office for a long time, I install a .forward file that both keeps a copy in my mail spool file and also pipes it through an autoreply "I'm not here" process.

To do that, the .forward file looks like this:

\graff, "|/usr/bin/vacation graff"
[download]

I'm not sure what will happen if the process crashes. I do know that if the mode on .forward isn't rw-r--r--, my mail server will bounce all mail sent to graff, 'cuz any other mode is either unworkable or a nasty security no-no. I'm not sure, but I might expect it to look up the pipeline process too, to make sure it's not an open door.

(Presumably, if I only want the mail to go to the process, I just leave off the first part of the line.)