If all else fails, you may want to ask your user to find another job. [/Joke]
Actually, your user may want to determine whether it's a company policy to disallow webmail. If so, accessing it via another url still violates that and may land him or her some trouble. If not, your user may want to appeal to some higher authority (than say their technology department where some low-level officials could well be simply making up their very own silly filters).
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