I want to customize the login screen of the webmail client?
The Login screen says Username (instead of email address) and some users get confused about this and complain about login failures because they don't enter their full email address to associate with a domain. My server is hosting more than one domain.

Also is it possible to add a company logo on the login screen and the main web mail screen? How can I do it? I do not exactly want to remove the Zimbra logo but I want to add something that will say something about my site. Is there a file that I need to hack to do this?

Also is there a way of passing parameters to Zimbra through http so that I can bypass the defacto Zimbra login screen?

I am using ZCS 4.5.3 Network Edition.