Thanks Mike! Your detailed reply has been very helpful for me. I didn't expect Zimbra to contain this amount of ongoing bug fixes.
3. "zmprov gmi
user@domain.com" is able to resolve my issue. It will be great if this information is made available at admin console's account properties for administrator's convenient and speed.
btw, knowing where the mailboxes are kept is useful for backup. But how do we restore it? Simply copying the msg files from the backup alone is not enough to recovery these emails backup to the account mailboxes. What else is required to get it shown up?
5. CLI command is very useful too. It will be great if there is a GUI version that run directly from the Linux System Preference so that the administrator can check and manage everything under a single interface without having to memorized so many commands.
I think Zimbra shared very similar situation as Linux - these software are designed by geeks for geeks. I do hope that the admin and management tools can be redesigned to be more user friendly so that it can be more widely accepted by the mass in order to convert them from Microsoft Windows and Exchange.
> We've put a warning in the documentation, and if you think an additional prompt is needed in the command itself feel free to file an RFE.
I believe additional prompt is a must for any potential harmful execution. This is pretty standard for most OS command that could be potential dangerous. So how do I proceed to file an RFE for this?
8. "Admin console gui > Account > Preferences tab > Allow sending email from any address" is exactly what I have been searching for! Thanks!
> Sound's like your currently using a contact folder shared with everyone@ company wide waiting for: Bug 29697 - External (non-Zimbra) addresses in GAL & Bug 21879 - Add non-Zimbra email addresses to GAL > Bug 14531 - GAL via contacts folders with sorting, browsing and real sync
It's funny that these missing features are considered bugs.

But how come these "awaiting bugs" have all their status label as resolved and closed? Does that mean that they have already been fixed and will be available soon in the new version?
> This should be fixed in 5.0.12+: Bug 34539 - inline images wont display in ajax client
Do I have to remove the older version when installing the new version?
btw, I read that 5.0.12 has some serious bug that was fixed with 5.0.13. Thus, is it advisable not to install the latest version until it's more stable?
> Provided your trying the latest ZD, yes a pic and the contents of a 'show original' would help / should be added to bugzilla. Be sure to specify languages tried.
The user is using the AJAX client, not the Desktop version. When I switch the preference back to HTML, the content does not disappear anymore. Weird.
Boon Hong.