[Dovecot] dovecot proxying with imapc

[suja]

Dear sir,

I have to set up a mail gateway which will be explored to Internet and a 
secure mail server in the Intranet.
I need a smart imap proxy in the mail gateway which will fetch the mail from 
server and present to user through either a stand alone mail client or a web 
mail client.
All authentication is through ldap server.

I followed the instructions given in 
http://wiki2.dovecot.org/HowTo/ImapcProxy
But while logging in I am getting a error:

dovecot: imap(user1): Error: user user1:Initialization failed: Initializing 
mail storage from mail_location setting failed: Unknown mail storage driver 
imapc
dovecot: imap(user1): Error: Invalid user settings. Refer to server log for 
more information.

I couldn't figure out what is wrong. Please help me to sort it out.

Thanks & Regards,

Suja PV
LEOS

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