The vacation program, when run from inside your ~/.forward file, figures out the location of your database file and message file by looking up your username in the passwd(5) file. This method of finding those files will fail, however, if the user's account has been removed.

Beginning with V8.12 sendmail you can turn off this lookup of the user identity in the passwd(5) file. But if you do that, you will need to specify the location of the database file and the message file with the corresponding -f and -m command-line switches:

|"/usr/ucb/vacation -U -f /admin/retired/bob.db -m /admin/retired/bob.msg bob"

This method of bypassing the passwd(5) file could be handy in the aliases database as a means of handling retired users:

bob: |"/usr/ucb/vacation -U -f /admin/retired/bob.db -m /admin/retired/bob.msg bob"

The -U suppresses a lookup of bob in the passwd(5) file (which would fail because bob no longer has an account). The -f command-line switch (-f) tells vacation the path and filename of the database it should use. The -m command-line switch (-f) tells vacation the path and filename of the message file it should use.

If -U is specified, and if either the -f or -m, or both, are omitted, vacation logs or prints the following error and exits EX_NOINPUT:

vacation: -U requires setting both -f and -m