The good news is that you supplied all the right info in this forum to solve your problem
To save you from any future hassles and errors you definitely need to look closely at all errors and instructions supplied by Zimbra to ensure a smooth installation.
First problem I see is that you are trying to install a package of Zimbra designed for Ubuntu 6.0.4 onto Ubuntu 8.0.4. as indicated by first message
Code:
WARNING: ZCS is currently only supported on Ubuntu Server 6.06 LTS.
You are attempting to install on Ubuntu 8.04 which may not work.
I strongly suggest you use the latest version of Zimbra kindly provided by dijichi2 which has been built especially for Ubuntu 8.04
It can be found
here for download.
The next issue is your hosts file.
It is really important that you have a fully qualified domain name as email addresses use the domain and not the hostname of a computer.
The message below from your screenshot indicated this
Code:
ERROR: Installation can not proceeed. Please fix your /etc/hosts file to contain:
ip FQHN HN
If you look at your hosts file, it does not follow this format.
You need to change the line
Code:
192.168.7.161 mailserver mail
To something similar to (where yourdomain.com is your actual domain name as defined in the DNS server you use)
Code:
192.168.7.161 mail.yourdomain.com mail
Which leads me to the next thing you may have trouble with, you need to have setup a proper DNS record for the host you have in your hosts file (ie an A record and MX record).
If you are unsure what these things mean, check out the Zimbra Wiki, or search the forums, or even search the internet on instruction for setting up DNS server for ubuntu.
Hope this helps.