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5.0.14 is out, check with your system admin on your planned upgrade date; or point them at this page to look into doing the quick ZmKeys.properties modification I've listed above.
-Mandatory spellcheck before send isn't till 6.0 so can't use that.
-One could modify the classify check zimlet, the dirty words alerter zimlet, or even the attachment checker zimlet (available in the source/gallery) to essentially do what you want, but they're not user installable, unless your using ZD.