At first - I think that Zimbra is very interesting piece of software. Currently I'm evaluating it, in the same time I'm learning linux, postfix, spamassassin etc. so it it great experience for me. Already I have one production box as mail gateway and I plan to use it throughout the company. I have some comments/wishes to the Zimbra web interface for next releases:
1. I'm missing possibility to quickly navigate through messages. Imagine there are thousands of messages in folder and all I can use are left and right arrows. It would be great if there are more navigation controls, for example pages (1,2,3,4,5...10), or dates (today, yesterday, ...) or maybe there should be possibility to see more messages per page than 100. I know that there is the search option, but I think it could be even better.
2. I like to see messages' complete received/sent date and time. In Zimbra I can see it on today's messages, but on older messages I see only the date, no time. And date is in the IV 12 format, is there a way to change it to european 12.4.2006 format? I really don't like current format.
3. In the user options, there is possibility to set "Group mail by". There should be another option "Reading pane". When grouping is set by message, here will be set if reading pane is on/off by default.
Sorry if I missed some already existing features that address my comments. Keep up the good work!