I'm trying to change the sender's address from my Entourage's default
Address to that of a separate account.

I've tried this:
set strRecipientAddr to "[log in to unmask]"
set strSenderAddr to "[log in to unmask]"
set strRecipientName to "DMM"
set subjectvar to "File has been sent"
tell application "Microsoft Entourage"
  set composeMessage to (a reference to (make new outgoing message ¬
  with properties {sender:strSenderAddr,
recipient:{address:strRecipientAddr, display name:strRecipientName, ¬
  recipient type:to recipient}, subject:subjectvar}))
 send composeMessage
end tell

But it continues to send from the default address of
[log in to unmask] How can I change the default address?

Any advise would be appreciated?

Regards
David McMillan
SelectSpecs.com