Enchanted with joy, we read emails from those with whom we feared losing contact. Writing these notes on occasion is just as gratifying, of course.
Let us not have obligations dampen and shorten the joy — obligations such as questions the recipient feels she should answer but just right now dos not have the time, leisure and mind to do in a way she would like. Spare the questions, spread the elation, and get a reply immediately (or, well, at all).
Not all emails need bring joy and charm, of course. It is prudent, then, not to have Sparrow connect to remote servers and download images automatically, for example; better have it ask you first:
›› Remote images in emails can let senders know that you opened their message -- and when, and possibly where. In Sparrow, it's easy to turn off automatic downloading of such images; it's easy to see select graphics, too.