postfix docs

[Matthias Andree]

Tom Allison wrote:
> I went back to my docs and was reading an example to impliment with postfix.
> 
> I'm just curious what this:
> 
>   exec <msg.$$ || exit $EX_TEMPFAIL
> 
> does.  'exec' ???

exec <msg.$$    just sets an input redirection for the running script that
persists until the script exits (otherwise, redirections are local to the
pipeline or command with which they are specified).

The appended    || exit $EX_TEMPFAIL    means "if we cannot redirect, exit
with code $EX_TEMPFAIL".

HTH,
Matthias