Business letter; formal?

In a business letter

(Majority in this favor:)
HVS: In modern business letters, "herewith" .....  Even if one allows "herewith", .... either be formal or informal, but don't mix them up. .....
(Then, a preferred form)
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(So far, one thinks this way)
E.W: I disagree. .... exactness and accuracy ....