Interworking of cron and sendmail applets

[Kaarle Ritvanen]

On Tue, 21 Jan 2014, Harald Becker wrote:

> Beside modifying the Busybox binary, you can create a script file
> for sendmail:
>
> #!/bin/sh
> exec /bin/busybox sendmail -f ... "$@"
>
> install this script as your sendmail and make it executable
> (chmod +x). Then cron shall pickup this script for sendmail and
> the script will add the missing information.

Of course, there are ways to hack around the problem, but I prefer a 
solution that's easy to replicate in multiple environments with minimum 
hassle.

I would like to understand why the sendmail applet requires the use of the 
-f option. It used to be optional, but it was made mandatory in commit 
88b8f0a, which has an informative commit log message: "sendmail: update by 
Vladimir". I suggest the -f option be made optional again unless there are 
good reasons not to do so.

BR,
Kaarle