[fetchmail-users] injecting message and header rewrite

[Payal R. <pay...@sc...>]

Hi,
I have read the docs and faq but am quite confused with "header rewrite" 
option. I want to download mails from server X (sendmail) for my domain 
example.com, by fetchmail and inject in my localhost (qmail) - clean it 
for viruses and spam and forward it to server Y (which can be anything).
qmail will route the messages through control/smtproutes files. What are 
the options I require for fetchmail, do I need to play with headers?  
Server Y is not in my control (it may be exchange server or MDaemon) and 
is set to receive mails for example.com
Any ideas please?
With warm regards,
-Payal