下载编译c-client.tar.Z
  wget ftp://ftp.cac.washington.edu/imap/c-client.tar.Z
  gunzip c-client.tar.Z
  tar xvf c-client.tar
  cd imap-2007e
  make  lr5  EXTRACFLAGS="-fPIC"
  (lr5 Redhat5及以上 CentOS5以上 Redhat4 使用 lrh)
  cp -pfr c-client /usr/local/imap-c-client
  mkdir /usr/local/imap-c-client/lib
  cp /usr/local/imap-c-client/c-client.a /usr/local/imap-c-client/lib/libc-client.a

编译php

以前部署nginx时，php安装在/data0/software/php-5.2.13/，所以我在原来的编译上再加上--with-imap=/usr/local/imap-c-client --with-imap-ssl ，下面以粗体显示。

cd /data0/software/php-5.2.13/
./configure --prefix=/usr/local/webserver/php --with-config-file-path=/usr/local/webserver/php/etc --with-mysql=/usr/local/webserver/mysql --with-mysqli=/usr/local/webserver/mysql/bin/mysql_config --with-iconv-dir=/usr/local --with-freetype-dir --with-jpeg-dir --with-png-dir --with-zlib --with-libxml-dir=/usr --enable-xml --disable-rpath --enable-discard-path --enable-safe-mode --enable-bcmath --enable-shmop --enable-sysvsem --enable-inline-optimization --with-curl --with-curlwrappers --enable-mbregex --enable-fastcgi --enable-fpm --enable-force-cgi-redirect --enable-mbstring --with-mcrypt --with-gd --enable-gd-native-ttf --with-openssl --with-mhash --enable-pcntl --enable-sockets --with-ldap --with-ldap-sasl --with-xmlrpc --with-imap=/usr/local/imap-c-client --with-imap-ssl --enable-zip --enable-soap 

make ZEND_EXTRA_LIBS='-liconv'
make install

重新启动php&nginx

测试一下应用，成功了.