spam emails with | in front of the email addresses

3 msg	Re: Virtual domain aliases
4 msg	address verify vs. virtual_alias_maps
20 msg	Postfix/ClamAV Config Error
4 msg	smtp /dev/poll problem
6 msg	Addresses filtering for only one supported domain
14 msg	Greylist question
1 msg	One transport with AUTH and other transport wit...
7 msg	Is this expected reject behavior for foreign IP...
3 msg	relay_domains and virtual_mailbox_domains not w...
2 msg	Need help debugging a possible content filter p...

spam emails with \| in front of the email addresses
\ Vinay Kumar (27 Nov 2007)
. \ Victor Duchovni (27 Nov 2007)
. . \ Vinay Kumar (27 Nov 2007)
. . . \ Charles Marcus (27 Nov 2007)
. . . . \ Vinay Kumar (27 Nov 2007)
. . . . . \ Victor Duchovni (27 Nov 2007)
. . . . . . \ Listaccount (28 Nov 2007)
. . . \ Victor Duchovni (27 Nov 2007)
. . . . \ vinay kumar (27 Nov 2007)
. \ (Wietse Venema) (27 Nov 2007)
. . \ casfre (27 Nov 2007)

9 msg	unexpected domain rewrite (by postfix?)
5 msg	Error receiving email
20 msg	Postfix 2.5-20071111, smtp.gmail.com, bouncing ...
1 msg	Bounce notification configure
45 msg	Re: Recipient validation
2 msg	Use of MySQL for lookups
8 msg	proposal: change behavior with respect to recip...
11 msg	OT: Any bad DKIM experiences?
8 msg	hashed spool directories

Subject:	spam emails with \| in front of the email addresses
Group:	Postfix-users
From:	Vinay Kumar
Date:	27 Nov 2007

I use postfix as gateways to our exchange servers.

I am seeing a lot of spam with |username. I use
relay_recipients file for specifying the know users to postfix. In the
postfix logs i don't see the | symbol. I am assuming that the postfix
strips it and sees it as a external command. Is that true..

I don't want to accept any email with |username .. is there
a way to do that.

thanks

/khanda