I am using 4.5.7, and 5.0beta3 as testing servers. I expected to implement Zimbra as my company email system. However, some bugs are critical that need to solve first.

1. I dont know why I need to enable GAL access if I want to search shared contacts when compose new mail.
2. Compose new mail, press "To:", using "." as searching text. Only show partial of contacts.
3. mail queues are not function in 5.0beta3. Seems stat service is not running.
4. Antivirus service seems failed to start. even extend startup interval from 120 to 180.

I knew some of the bugs had been reported already, but there still has no solution.
Furthermore, if Zimbra has following enhancements, I think it will be much more attractive.

1. In list view of mails, there can have custom fields I can choice. From and To field are needed in Inbox/Sent box, bcoz users often have multiple alias(identity), we need to know who is the target recipient/sender in list view.
2. Can choose the message encoding. Some poor mail client may send message without specify encoding or wrong encoding. Its very common.
3. Can COPY email from a folder to another. bcoz I filter my emails into folders by organisations, companies or persons. Sometimes email may be related to two groups. The easiest way is I can find the message in both folders.
4. can set the "mark message as READ" time interval.
5. adding attachments method is not user friendly enougth. Especially adding multiple attachments.
6. have PDF first page preview