Actionmailer ignores return-path setting

Rails
1

Hello,

i have the problem that i want to set the return-path to the envelope
of outgoing emails so bounces can be handled. I tried to set the
header as followed in my mailer class:

def newsletter
subject ‘subject’
reply_to ‘[email protected]’
from ‘[email protected]’
recipients ‘[email protected]’
sent_on Time.now
body :body => ‘content’
headers ‘return-path’ => ‘[email protected]’
end

However, in the outgoing email the return path is automatically set to
‘[email protected]’

I am using Rails 2.3.3 and Postfix 2.3

can anyone point me to the correct setting to set the return-path?

Greets
-act