We have been using Zimbra now for a couple of months. We are very happy with the way it works, but using it I came accross some quirks that could be improved so here I share with you guys :
1) Copy/Paste should work with every type of document. For example, co-workers aren't able to copy paste a piece of excel document (some tables for example), the tables won't appear, and sometimes not even the text in it. I suppose this is a formating problem, but it should be possible, it's a big functionality hog for us here.
Same with images, or even attachements, you can't just copy paste them inside de document.
I suppose that for the webonly version of Zimbra that could be difficult to implement, but maybe in the Desktop edition where you have things running localy, that could be resolved.
2) Once a document attached (or copy pasted inside the mail), to be able to edit it and send it, but without modifying the original. If think that when outlook attaches a mail, it directly creates the temporary file that will be joined to the mail, and when you are editing it, it does it directly on the temp file and not the original.
3) In the desktop edition to have all the different modules of Zimbra available (Documents, IM, future Briefcase). I know that you can't sync all this, but at least having them and beeing able to use them if you are online. If your are not, just get a message telling you that you are offline.
Maybe this will be on in the next release of ZM Desktop.
4) When you open a document attached to a mail, not right away download it to be able to read it, but give the option of opening it stored in the virtual memory, or download it. (I have experienced this on mac mostly)
5) You can empty you inbox folder without having to delete manualy every mail in it. Beeing able to do this with ANY folder would be great.
6) Future Briefcase, you have to upload the files you want to be available later on. A solution like the one in Alfresco would be amazing. You can just add folders that are real shares on the local network where your server is. And beeing able to navigate in different folders. That way, you can access you network share from anywhere, and you don't have to worry having to upload something or having missed on file in the upload before leaving, and everything would be synced always.
Also, beeing able to upload from other places to the server of course.
For editing the files, doing it localy is not a mess... but then you would have to upload again, then overwriting the file, etc...
Some sort of WebDav folder thing could be great, so you edit the file like you where at work.
This is a lot asking I know, but the Alfresco type of navigation is imho the best way to go. You always have your content (all of it) without having to worry about having uploaded or not. The opensource version have this... maybe you could check this out.
7) Zimlets should be synced also with the Desktop version, so you get exactly the same config.
Have more ideas but they won't come to my mind right now... I will keep this post to date with submissions from people here so you people can check it out.
Thanks for the great piece of software that Zimbra is.