Mail setup correctly but asks for Imap Libraries

Hello I have setup Email with Postfix, Dovecot and MySQL on Debian 6 (Squeeze) as per: https://library.linode.com/email/postfi … -6-squeeze">https://library.linode.com/email/postfix/dovecot-mysql-debian-6-squeeze

It is configured correctly and works through Thunderbird.

However SugarCrm throws this error.

"Inbound Email cannot function without the IMAP c-client libraries enabled/compiled with the PHP module."

Are there other IMAP libraries I need to install?