On Sat, Feb 22 2003, Lars Magne Ingebrigtsen wrote:

[ `mail-source-delete-old-incoming' ] 
> I'm not quite sure that such a function is a good idea.  The
> Incoming* files are created only by pretest Gnusae, so they should
> only be produced by versions of Gnus that are dangerous, mail-wise
> speaking.  Having mechanisms for automatically deleting stuff in
> such a situation might be counterproductive.

The default value of `mail-source-delete-incoming' should still be
`nil' in pretest Gnusae, i.e. no automatically deleting, no change to
the current behavior.

I don't see any harm if Gnus would offer an option to delete old
files.  Note that additionally there's a `confirm' argument in
`mail-source-delete-old-incoming' and a variable
`mail-source-delete-old-incoming-confirm'.

I.e. the user has to change `mail-source-delete-incoming' to a
positive integer (default is nil) *and* change
`mail-source-delete-old-incoming-confirm' to nil (default is t) in
order to get automatic deleting without confirmation for every single
incoming file.  I suppose this should be enough protection. :-)

I'll add proper documentation, if this patch will be accepted.

--8<---------------cut here---------------start------------->8---
2003-02-24  Reiner Steib  <Reiner.Steib@gmx.de>

	* mail-source.el (mail-source-delete-incoming): Allow integer value.
	(mail-source-delete-old-incoming-confirm): New variable.
	(mail-source-delete-old-incoming): Use it.  New function.
	(mail-source-callback): Call `mail-source-delete-old-incoming' if
	`mail-source-delete-incoming' is a nonnegative integer.
--8<---------------cut here---------------end--------------->8---

Here's a revised version[1] of the patch: