我正在使用 Debian Squeeze 尝试安装 iRedMail（http://www.iredmail.org/）这是我收到的错误：
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
libapache2-mod-php5 : Depends: libdb5.1 but it is not installable
Depends: libssl1.0.0 (>= 1.0.0) but it is not installable
Depends: libxml2 (>= 2.8.0) but 2.7.8.dfsg-2+squeeze7 is to be installed
php5-cli : Depends: libdb5.1 but it is not installable
Depends: libssl1.0.0 (>= 1.0.0) but it is not installable
Depends: libxml2 (>= 2.8.0) but 2.7.8.dfsg-2+squeeze7 is to be installed
Depends: libedit2 (>= 2.11-20080614-4) but 2.11-20080614-2 is to be installed
php5-common : Depends: psmisc (>= 22.15-1~) but 22.11-1 is to be installed
php5-gd : Depends: libjpeg8 (>= 8c) but it is not going to be installed
php5-imap : Depends: libssl1.0.0 (>= 1.0.0) but it is not installable
php5-ldap : Depends: libsasl2-2 (>= 2.1.24) but 2.1.23.dfsg1-7 is to be installed
php5-mcrypt : Depends: libltdl7 (>= 2.4.2) but 2.2.6b-2 is to be installed
php5-mysql : Depends: libmysqlclient18 (>= 5.5.24+dfsg-1) but it is not installable
php5-pgsql : Depends: libpq5 (>= 9.0~) but 8.4.17-0squeeze1 is to be installed
E: Broken packages
< ERROR > Installation failed, please check the terminal output.