I tried to install claws-mail; but got the response that follows. Please help me fix the error.
baranidaran@baranidaran-LIFEBOOK-AH502:~$ sudo apt-get install claws-mail [sudo] password for baranidaran: Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: libstlport4.6ldbl thunderbird-globalmenu gwibber-service libgtkspell-3-0 gir1.2-ubuntuoneui-3.0 libreoffice-emailmerge libgwibber-gtk2 libcmis-0.2-0 libubuntuoneui-3.0-1 python-speechd gwibber-service-twitter liblouis2 python-brlapi libgwibber2 python-louis gwibber-service-identica python-libproxy python-egenix-mxdatetime python-egenix-mxtools python-pyatspi2 gwibber-service-facebook liblouis-data gstreamer0.10-gnonlin Use 'apt-get autoremove' to remove them. The following extra packages will be installed: claws-mail-i18n Suggested packages: claws-mail-doc claws-mail-tools The following NEW packages will be installed: claws-mail claws-mail-i18n 0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded. 2 not fully installed or removed. Need to get 3,523 kB of archives. After this operation, 9,933 kB of additional disk space will be used. Do you want to continue [Y/n]? y Get:1 http://in.archive.ubuntu.com/ubuntu/ precise/universe claws-mail i386 3.8.0-1ubuntu1 [1,577 kB] Get:2 http://in.archive.ubuntu.com/ubuntu/ precise/universe claws-mail-i18n all 3.8.0-1ubuntu1 [1,946 kB] 64% [2 claws-mail-i18n 684 kB/1,946 kB 35%] 64% [2 claws-mail-i18n 684 kB/1,946 kB 35%] Get:3 http: //in.archive.ubuntu.com/ubuntu/precise/universe claws-mail-i18n all 3.8.0-1ubuntu1 [1,946 kB] Fetched 2,838 kB in 11min 30s (4,110 B/s) Selecting previously unselected package claws-mail. (Reading database ... 238749 files and directories currently installed.) Unpacking claws-mail (from .../claws-mail_3.8.0-1ubuntu1_i386.deb) ... Selecting previously unselected package claws-mail-i18n. Unpacking claws-mail-i18n (from .../claws-mail-i18n_3.8.0-1ubuntu1_all.deb) ... Processing triggers for man-db ... Processing triggers for desktop-file-utils ... Processing triggers for bamfdaemon ... Rebuilding /usr/share/applications/bamf.index... Processing triggers for gnome-menus ... Processing triggers for hicolor-icon-theme ... Setting up qmail (1.06-4) ... The hostname -f command returned: $1 Your system needs to have a fully qualified domain name (fqdn) in order to install the var-qmail packages. Installation aborted. dpkg: error processing qmail (--configure): subprocess installed post-installation script returned error exit status 1 No apport report written because MaxReports is reached already dpkg: dependency problems prevent configuration of qmail-run: qmail-run depends on qmail (>= 1.06-2.1); however: Package qmail is not configured yet. dpkg: error processing qmail-run (--configure): dependency problems - leaving unconfigured No apport report written because MaxReports is reached already Setting up claws-mail (3.8.0-1ubuntu1) ... Setting up claws-mail-i18n (3.8.0-1ubuntu1) ... Errors were encountered while processing: qmail qmail-run E: Sub-process /usr/bin/dpkg returned an error code (1)