How should email subject lines be written? Like this:
Question Regarding Tomorrow's Meeting
or like this:
Question regarding tomorrow's meeting
For some reason, I would consider the latter to be less "professional." However, capitalizing each word as in a title may be a bit tedious, and it may even look awkward if someone has many emails with capitalized titles. Furthermore, this website seems to suggest that the people are less likely to click on an email if each word is capitalized (though I'd probably take that with a grain of salt).