Sendmail / Email copy - Fixed

[Tom 'Needs A Hat' Mitchell]

On Wed, Mar 17, 2004 at 02:57:24PM -0600, admin at kclinux.net wrote:
> 
> After playing around, I changed the line for this account:
> emergency: SPRINT-PCS-EMAIL,SPRINT-PCS-EMAIL,SPRINT-PCS-EMAIL,PAGER-NUMER
> to this:
> emergency:
> SPRINT-PCS-EMAIL,SPRINT-PCS-EMAIL,SPRINT-PCS-EMAIL,PAGER-NUMER,emergency
> 
> Adding the emergency to the end of the line got the emails going back to the
> local account, and it's now going to all the PCS phones and pager.

Remember that you can escape expansion in aliases.  If you look at it
you had built a loop:

  emergency: them, us, emergency

Think about how the loop expands, Compare with 

  emergency: them, us, \emergency

What if you had done this ;)  

  emergency: them, us
  them:	     bob, carol, ted, emergency
  us:	     fred, jed, alice, emergency

Could you detect it and find it to fix it.
What if one of these involved aliases on a second machine?
What if one user had a bad vacation script?  ;-)

The good news is that the newer sendmail is smart enough to not do bad
things for the simple errors.  At one time it would hurl big chunks.
But garbage in is still garbage out....

-- 
	T o m  M i t c h e l l 
	/dev/null the ultimate in secure storage.