Are you flagging that email as high importance? Or Urgent?
This quote
Given the choice between working on the important and the urgent, the urgent almost always wins.
from Misjudging risk (and bad decisions) made me realise something about email, and Outlook in particular. When using outlook for email, like I do at work, you can flag an email with an importance level of high, medium or low. This isn't something I usually change from the default setting of medium but others sometimes flag things as high. But do they really mean that this message is really important or do they mean it's urgent? I would suggest it is used to mean the latter, to make it stand out and be attended to. The mac Mail application calls this field Priority - which would seem to be a more correct term.
Additionally you can't change that flag for different people - if you're copying me into your email, then by nature of being copied in there should be no action for me to take, it's for information only - in which case why does it still have a red exclamation mark showing it to be important on it?
Not to mention who is it urgent for? The sender or the recipient? Usually its the former, in which case wouldn't picking up a telephone, or dropping by the office be a much more effective way to elicit the information?