Rudolf-sensei's post on a Japanese person whose email message started with an unexpected apology made me smile. It sure is funny to apologize for sending email even if it's late at night. Unlike phone calls that can directly rob you of your time regardless of what you're doing, emails are a moderate means. You can, basically, send an email without worrying about disturbing the person. That should be one of the advantages of emails over phone calls.
Still, I kind of understand why the Japanese person started with an apology. The person (...by the way, is the person he or she? This is where I often feel annoyed when writing in English.) just wanted to be polite, I guess. And in that sense, it's nothing strange for the person's (Aagh! No, I'm determined not to use his/her or something like that this time. ;)) part. It's a rather usual practice for a Japanese to start an email message with some polite words when writing to someone you don't know very well. And those words are, in many cases, simply used like greetings, rather than taken as they are literally. Even if you know you don't need to when writing in some other language, sometimes you can't resist doing so, because you're in such a culture. I don't know whether the person (hehehe...) was aware of that or not. It's a possibility that the sender thought the receiver might open the email soon.
When calling someone late at night, a Japanese would say, 「夜分遅くすいません」(yabun osoku suimasen: I'm terribly sorry to call you at this late hour.). Well, to tell the truth, I almost did it in an email message the other day as well. Ha ha ha!