Error connecting to IMAP server: localhost. 115 : Operation now in progress [DirectAdmin]

This error seems to be caused by a bug in php:

[Wed May 12 15:48:08 2004] [error] PHP Warning: fsockopen(): unable to connect to
localhost:143 in /var/www/html/squirrelmail-1.4.2/functions/imap_general.php on line 454

Try recompiling everything from "clean".

cd /usr/local/directadmin/customapache
rm -f configure.*
./build clean
./build update
./build all
/sbin/service httpd restart

(or "/usr/local/etc/rc.d/httpd restart" for FreeBSD)