Since coming to China, I've noticed that a lot of the locals, coworkers and otherwise, have the phrase "Sincerely," or "Best regards" automatically in their email signature block, so it automatically gets appended to every email they send. In fact, while I was in school, a lot of the foreign grad students in the CS department did the same thing.
I guess they think of these phrases as lines that always ends correspondence written in the English language, without knowing its true meaning.
While one might argue that it's a time saver to put it in, and that's certainly a valid point, my line of thought is that it's a bit cheesy. How can you be honestly sure that you're "sincere" about what you write or be giving your "best regards" if that phrase is automatically included by a computer in each email message you write? To me, being sincere is a concious act of thought, and to type it out signifies that to the recipient.
But even amongst native English speakers, have we paused to think just about what the true meaning of our words -- even the routine greetings -- are, or are we just issuing them reflexively? Food for thought...
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