Email and Calendars with Zimbra 6 on CentOS 5

Zimbra is a groupware system that provides email, calendaring, integrated antivirus and spam filtering, and more for multiple domains. Available in several editions, this guide will help you get the Open Source Edition installed on your CentOS 5 Linode.

Please note that Zimbra is a fairly “heavy” (resource-intensive) product compared to some other groupware offerings. We recommend a Linode 2048 or higher for best results; you may encounter issues using Zimbra with lower-resource plans. Additionally, note that Zimbra works best as a standalone product on your Linode; installation alongside other common software such as web or email servers is not advised.

We assume you’ve already followed the steps outlined in our Setting Up and Securing a Compute Instance, and that your system is up to date. All configuration will be performed through the terminal; please make sure you’re logged into your Linode as root via SSH.

Installing Prerequisite Packages

Make sure your system is up to date by issuing the following command:

yum update

Issue the following command to install several packages required by Zimbra:

yum install gmp compat-libstdc++-33 sysstat sudo libidn wget

Depending on the requirements for the current version of Zimbra, you may need to install additional packages later. The install program will notify you if there additional packages are required.

System Files Prerequisites

Before proceeding, make sure your /etc/hosts file has valid entries. For reference, your file should resemble the following:

File: /etc/hosts

1 2	127.0.0.1 localhost.localdomain localhost 12.34.56.78 hostname.example.com hostname

Be sure to replace “12.34.56.78” with your Linode’s IP address. Replace “hostname.example.com” with your Linode’s fully qualified domain name. Next, make sure your hostname is set in /etc/hostname by issuing the following commands (insert your one-word hostname in place of “hostname”).

echo "hostname" > /etc/hostname
hostname -F /etc/hostname

Issue the following commands to check your setup:

hostname
hostname -f

The first command should return only the one-word hostname for your system, while the second command should return the system’s FQDN.

Installing Zimbra

Visit the download page for Zimbra Open Source Edition and copy the link to the current version of the software for RHEL 5 to your clipboard. Issue the following commands on your Linode via the shell to download and unpack the install package. Replace the filenames shown below after wget and tar with the current version.

wget http://files2.zimbra.com/downloads/6.0.7_GA/zcs-6.0.7_GA_2473.RHEL5.20100616214455.tgz
tar -xzf zcs-6.0.7_GA_2473.RHEL5.20100616214455.tgz

Switch to the install directory and launch the installer with the following commands. The “–platform-override” directive is necessary to instruct the installer to proceed on CentOS 5, as it is not an officially supported platform.

cd zcs-6.0.7_GA_2473.RHEL5.20100616214455
./install.sh --platform-override

You may receive a warning similar to the one shown below. Enter “Y” to proceed.

You appear to be installing packages on a platform different
than the platform for which they were built.

This platform is CentOS5
Packages found: RHEL5
This may or may not work.

Using packages for a platform in which they were not designed for
may result in an installation that is NOT usable. Your support
options may be limited if you choose to continue.


Install anyway? [N] Y

Before the install begins, you may receive a warning similar to the one shown below:

DNS ERROR resolving MX for archimedes.example.com
It is suggested that the domain name have an MX record configured in DNS
Change domain name? [Yes] No

It is recommended (but not required) that the fully qualified domain name for your system (hostname.example.com) have an MX record pointing to it. You may wish to visit your DNS control panel and add such a record now, or proceed if you won’t be receiving mail for your FQDN on this system (for example, if you’ll be receiving email for your base domain or others).

The install will continue, probably requiring a few minutes to perform various tasks. You’ll be asked which components of the Zimbra package you’d like to install. For the purposes of this tutorial, choose the default values for each (“Y” or “N” depending on which letter is in the brackets).

Once the installation has completed, you’ll be presented with an admin menu next.

Main menu

   1) Common Configuration:
   2) zimbra-ldap:                             Enabled
   3) zimbra-store:                            Enabled
        +Create Admin User:                    yes
        +Admin user to create:                 admin@archimedes.example.com
******* +Admin Password                        UNSET
        +Enable automated spam training:       yes
        +Spam training user:                   spam.pvsjtuws@archimedes.example.com
        +Non-spam(Ham) training user:          ham.apqv8ks8@archimedes.example.com
        +Global Documents Account:             wiki@archimedes.example.com
        +SMTP host:                            archimedes.example.com
        +Web server HTTP port:                 80
        +Web server HTTPS port:                443
        +Web server mode:                      http
        +IMAP server port:                     143
        +IMAP server SSL port:                 993
        +POP server port:                      110
        +POP server SSL port:                  995
        +Use spell check server:               yes
        +Spell server URL:                     http://archimedes.example.com:7780/aspell.php
        +Configure for use with mail proxy:    FALSE
        +Configure for use with web proxy:     FALSE

   4) zimbra-mta:                              Enabled
   5) zimbra-snmp:                             Enabled
   6) zimbra-logger:                           Enabled
   7) zimbra-spell:                            Enabled
   8) Default Class of Service Configuration:
   r) Start servers after configuration        yes
   s) Save config to file
   x) Expand menu
   q) Quit

Address unconfigured (**) items  (? - help) 3

Enter “3” to enter the zimbra-store menu, which will look similar to the following:

Store configuration

   1) Status:                                  Enabled
   2) Create Admin User:                       yes
   3) Admin user to create:                    admin@archimedes.example.com
** 4) Admin Password                           UNSET
   5) Enable automated spam training:          yes
   6) Spam training user:                      spam.pvsjtuws@archimedes.example.com
   7) Non-spam(Ham) training user:             ham.apqv8ks8@archimedes.example.com
   8) Global Documents Account:                wiki@archimedes.example.com
   9) SMTP host:                               archimedes.example.com
  10) Web server HTTP port:                    80
  11) Web server HTTPS port:                   443
  12) Web server mode:                         http
  13) IMAP server port:                        143
  14) IMAP server SSL port:                    993
  15) POP server port:                         110
  16) POP server SSL port:                     995
  17) Use spell check server:                  yes
  18) Spell server URL:                        http://archimedes.example.com:7780/aspell.php
  19) Configure for use with mail proxy:       FALSE
  20) Configure for use with web proxy:        FALSE

Select, or 'r' for previous menu [r] 4

You can configure various options here; but, the most important option is the one for setting the administrator password. Enter “4” to set it, choosing a strong password comprised of letters, numbers, and non-alphanumeric characters. After setting the admin password, enter “r” to return to the main menu. You will be asked to apply the new configuration. Type “a” and press enter. You may then allow the program to proceed with the remaining installation steps.

After installation has completed, you’ll need to start zimbra with the following command:

service zimbra start

To have Zimbra start on every boot, enter the following command:

chkconfig zimbra on

you may wish to reboot your Linode to make sure everything comes back up properly. After doing so, visit the Zimbra admin URL in your browser. It will be in the form https://hostname.example.com:7071/. You’ll need to accept the SSL certificate presented to access the admin panel, which you may then use to continue configuring your new Zimbra server. Enjoy!

Monitor for Software Updates and Security Notices

When running software compiled or installed directly from sources provided by upstream developers, you are responsible for monitoring updates, bug fixes, and security issues. After becoming aware of releases and potential issues, update your software to resolve flaws and prevent possible system compromise. Monitoring releases and maintaining up to date versions of all software is crucial for the security and integrity of a system.

Please monitor the Zimbra Updates page to ensure that you are aware of all updates to the software and can upgrade appropriately or apply patches and recompile as needed.

When upstream sources offer new releases, repeat the instructions for installing Zimbra and recompile your software when needed. These practices are crucial for the ongoing security and functioning of your system.

More Information

You may wish to consult the following resources for additional information on this topic. While these are provided in the hope that they will be useful, please note that we cannot vouch for the accuracy or timeliness of externally hosted materials.

• Zimbra Community Documentation
• Zimbra Wiki
• Zimbra Developer Zone