As a simple - and highly effective - spam control measure, I've been creating mail aliases just about every time somebody asks me for my address. E.g., if Joe at Joe's Hardware wants my address, I tell'm, "Sure! firstname.lastname@example.org!" And then, if I get spam, I can do two things: 1) turn the alias off and 2) go back to the source and call them out for selling / trading / whatever my address.
I've been doing this for several years; I have 266 aliases at this time.
When I look at my user account in the Zimbra admin control panel, and click the aliases tab, it takes a long time to load 266 aliases - and when it's done, all 266 display on one page. Whew!
That list should be segmented - it should be split into maybe 25-count chunks, like e-mail headers, and then displayed a chunck at a time.
My 2 cents.
PS: zmprov is a god-send!