Delivering Mail to Shared Folder with Spaces in Pathname

On our 10.3.8 mail server, I have some IMAP Shared Folders defined for each of our customer sites.

Customer eStores/Store Name 1
Customer eStores/Store Name 2
Customer eStores/Store Name 3

I’m trying to configure our Postfix alias file so that each of these Shared Folders can have their own e-mail address. Here’s what I added to my /etc/postfix/aliases file:

store1: "bb+Customer eStores/Store Name 1"
store2: "bb+Customer eStores/Store Name 2"
store3: "bb+Customer eStores/Store Name 3"

When I try to send e-mail to one of these three e-mail addresses (like store1@mydomain.com) I get a rejection from Postfix, like so:

This is the Postfix program at host mail.mydomain.com.

I'm sorry to have to inform you that the message returned
below could not be delivered to one or more destinations.

For further assistance, please send mail to <postmaster>

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

			The Postfix program

<"bb+Customer eStores/Store name 1"@mydomain.com>: data
    format error. Command output: bb+Customer eStores/Store Name 1: Bad protocol
?
Reporting-MTA: dns; mail.mydomain.com
Arrival-Date: Mon, 16 May 2005 14:45:22 -0500 (CDT)

Final-Recipient: rfc822; "bb+Customer eStores/Store Name 1"@mydomain.com
Action: failed
Status: 5.0.0
Diagnostic-Code: X-Postfix; data format error. Command output: bb+Customer eStores/Store Name 1: Bad protocol

Obviously, Postfix doesn’t like the spaces.

I know I can change the spaces to underscores in the Shared Folders’ pathnames, but I’d much rather prefer to retain the whitespace for its elegance and easy legibility.

Any ideas?