cd php-5.2.17/ext/imap
/usr/local/php/bin/phpize
./configure --with-php-config=/usr/local/php/bin/php-config --with-kerberos --with-imap-ssl
make
make install编译时如遇到错误：
configure: error: utf8_mime2text() has new signature, but U8T_CANONICAL is missing. This should not happen. Check config.log for additional information.安装imap库：
yum install libc-client-devel加载imap到php配置文件：
extension_dir = "/usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/"
extension=imap.so