Help installing Icedove

Hi,

I'm new, and a big ignorant on GNU/Linux, so please take it into account for your explanations.

I would like to install Icedove, but don't know how. Could anyone please explain step by step? Thank you very much in advance!

I tried to install it, but after entering 'sudo apt-get install icedove' I got this:

Reading package lists... Done
Building dependency tree
Reading state information... Done
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:
icedove : Depends: libfontconfig1 (>= 2.11) but 2.8.0-3ubuntu9.1 is to be installed
Depends: libglib2.0-0 (>= 2.37.3) but 2.32.4-0ubuntu1 is to be installed
Depends: libhunspell-1.3-0 (>= 1.3.3) but 1.3.2-4 is to be installed
Depends: libnspr4 (>= 2:4.10.3) but 4.9.5-0ubuntu0.12.04.3 is to be installed
Depends: libnss3 (>= 2:3.16.1) but 3.15.4-0ubuntu0.12.04.2 is to be installed
Depends: libpango-1.0-0 (>= 1.14.0) but it is not installable
Depends: libpangocairo-1.0-0 (>= 1.14.0) but it is not installable
Depends: libpangoft2-1.0-0 (>= 1.14.0) but it is not installable
Depends: libstdc++6 (>= 4.9) but 4.6.3-1ubuntu5 is to be installed
Depends: libvpx1 (>= 1.3.0) but 1.0.0-1 is to be installed
E: Unable to correct problems, you have held broken packages.