I have been using both Desktop and the web version, and while I prefer the Desktop, the spell checker does not work properly (it does work with the web version). I have read the forums and it sounds like a standard English spell check is installed by default, but it is not catching most spelling errors (usually very bad typos). Sometimes it does catch an error (little red dot underline), but it happens for only a small fraction of spelling errors. I always install new updates for Zimbra, but this has had no effect. Also I am having the exact same problem with a new computer and a new install.
Anyone else having this problem? Thanks.