While we feel that exclamation points give emphasis, always take an extra second or two to think about how your use of that most over-used punctuation will be perceived. Does it come across professional in the context of your writing? And in that light, I personally cannot think of a situation where two exclamation points will be more effective in directing your reader to take action than one. You have more tools in your arsenal, like bold and italics. Hell!... use all three at once before you use multiple exclamation points, I say.
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