/usr/spool/mail: 0777 or 0755?

[Guy Harris]

>     We run a 4.1bsd system, and have recently been having a discussion
> about mailbox protection.  One suggestion was that /usr/spool/mail should
> be writable only by root.

	.
	.
	.

> 	2) What other effects (good or bad) are caused by not having
> 	   /usr/spool/mail world-writable?

Well, the mailbox locking protocol requires the mail reader to be able to
create directory entries in /usr/spool/mail, which is a botch and causes
the mail readers to spend several seconds trying fruitlessly to lock the
mailboxes when entered if /usr/spool/mail isn't world-writable.

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy