[Plugin: Postie] Undefined function imap_open()

Hi,

Despite having Postie configured to use the POP3 mail protocol, I get these errors in the log file:

PHP Fatal error: Call to undefined function imap_open() in /var/www/wordpress/wp-content/plugins/postie/postieIMAP.php on line 78

Subsequently, Postie does not seem to be able to open the configured mailbox.

http://wordpress.org/extend/plugins/postie/