[fetchmail-users] Re: unsafe MDA procmail recommended by fetchmail

[Thomas W. <to...@to...>]

Sunil Shetye wrote:
> Quoting from Michelle Konzack's mail on Mon, Nov 07, 2005 at 07:29:19PM +0100:
> > ...
> > I think, procmail should have an config option to stop
> > this behaviour and return an error instead.
> > ...
> 
> procmail has a way of returning with an error. You may append the
> lines below to your procmailrc for error handling.
> ...
> ==========================================================================
> 
> # if procmail has reached here, delivery has failed. return with a
> # temporary failure code from <sysexits.h>.
> # 75 = EX_TEMPFAIL
> EXITCODE=75
> :0
> /dev/null
> ==========================================================================

So that may work, but it is really an obscure trick.
Fetchmail needs to have an easy-to-use, well-documented facility to 
configure its error behaviour in an obvious way.


> WARNING: the above recipe works only when the program invoking
> procmail handles the exit code gracefully. Otherwise, all your mails
> will be trashed.
> 
> fetchmail will not delete these mails. Even, most SMTP servers should
> queue up such mails for a few days before bouncing them back. But, if
> you have other programs invoking procmail, you will need to check if
> they handle such exit codes gracefully.

That other program may often be formail. While formail -s does 
propagate an error return code here, this is not reliable because it's 
not documented. Should be fixed.


Kind regards,
Thomas Wolff