Reply Address on Auto respond mail.

[Scott Ryan <scottr@xxxxxxxxxxxxxxxxx>]

I have an entry in my ldap to enable auto response. But when the response to 
the original sender has the incorrect return to address.

ldap entry: (cut for convenience)

mailAlternateAddress: my_domain_net-scott@xxxxxxxxxxxxx
accountStatus: active
deliveryMode: reply
mailReplyText: Out of Office - Until I am back

When a mail is sent to scott@xxxxxxxxxxxxx, the reply message is correct but 
the return address is:

Subject : [Auto-Reply] test auto 1
 Date: Today 16:31:20
 From: my_domain_net-scott@xxxxxxxxxxxxx
 To: scottr@xxxxxxxxxxxxxxxxx
 
Out of Office - Until I am back

Is there something I must do to ensure that the return address is just 
scott@xxxxxxxxxxxxx ??

many thanks in advance