Using podebconf-report-po --postpone=foo took me through the entire process
before bailing at the end with:
    The --postpone and --mutt options require the perl Mail::Box package. Please install the Debian libmail-box-perl package if you want to use these options.

It would have been more helpful to exit early when the option was given, before
walking me through the options and asking me to edit the text etc.

A couple of other minor usability points:

The prompt given at the end was "Ready to send the emails, are you sure?
[y/N/e/?]", which made me worry that --postpone wasn't working and it was going
to send the mails anyway. I suppose there isn't much point in prompting in
postpone mode, but if it is going to prompt it should be something like "Read
to append the mails to $foo".

Secondly it would be nice to wrap that message to <80 characters.

Thanks,
Ian.