Mail Aliases work and don't work at the same time with virtual users

OK,

I have several mail aliases setup. Some are jsut a single mail forwards others are multiple forwards.

The ones with a single address are working just fine. the ones with more then 1 person does not.

Here is a example of my alias file. abuse::admin@example.com postmaster:::admin@example.com hostmaster:::admin@example.com webmaster:::admin@example.com purchase_orders::user1@example.com:user2@example.com info::user1@example.com:user2@example.com:user3@example.com

the last 2 items bounce back with this:

This is the mail system at host example.com.

I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to

If you do so, please include this problem report. You can delete your own text from the attached returned message.

The mail system

user1@example.com (expanded from purchase_orders@example.com): unknown user: "user1"

user2@example.com (expanded from purchase_orders@example.com): unknown user: "user2"

Final-Recipient: rfc822; user1@example.com Original-Recipient: rfc822;purchase_orders@example.com Action: failed Status: 5.1.1 Diagnostic-Code: X-Postfix; unknown user: "user1"

Final-Recipient: rfc822; user2@example.com Original-Recipient: rfc822;purchase_orders@example.com Action: failed Status: 5.1.1 Diagnostic-Code: X-Postfix; unknown user: "user2"

---------- Forwarded message ---------- From: ************************************ To: purchase_orders@example.com Date: Fri, 9 Jul 2010 11:31:12 -0400 Subject: test test

I'm not sure what other information you want, but login names are formated @. Operation system is CentOs 5. I'll post any other infomration you just need just ask.