Hmm, that's supposed to turn it off completely.  It's possible that it doesn't work with IETFHDR set, but I would be surprised if that were the case.  I'll do some checking...

Nathan

At 03:50 PM 2/20/2008 -0500, Mark Berman wrote:
>Nathan,
>
>I tried that. The "Sender:" line still came through. Is there some other
>config parameter that might be overriding it?
>
> - Mark
>
>On Wed, 20 Feb 2008 15:34:24 -0500, Nathan Brindle <[log in to unmask]> wrote:
>
>>Sender= None
>>
>>At 03:23 PM 2/20/2008 -0500, you wrote:
>>>Hi,
>>>
>>>I am trying to set up a series of lists meant to behave like sendmail
>>>aliases. The idea is to have an address like [log in to unmask] and let
>>>the department secretary control who gets mail sent to the address
>>>(subscriber control).
>>>
>>>In general I've got this working. Setting "Default-Options=IETFHDR" helped a
>>>lot. The problem is that certain email clients (meaning Outlook) take it
>>>upon themselves to read the "Sender:" header line and display it in the
>>>"From" field as "<Sender:> on behalf of <From:>.
>>>
>>>Seems like typical Microsoft making their own rules to me, but Outlook is so
>>>common I have to deal with it.
>>>
>>>Thanks for any help.
>>>
>>> - Mark