Not all caps

“It’s like a heart attack to trick you into opening the email,” she says. “It’s the internet equivalent of yelling, and no one likes to be yelled at. Scammers and people trying to spam your inbox use these techniques, and they’re no longer effective.” Users who wrote an email with an all-cap subject line received a reply 30 percent less often, according to a Boomerang study. If something is truly urgent, Moah recommends skipping all caps and simply stating the urgency in the subject. “If you have a deadline, explicitly state it in the subject line,” she says. While all caps are bad, a completely lowercase subject line is also bad. Emails that were started with a lowercase letter got a reply 28.4 percent of the time, compared to a 32.6 percent response rate for those with proper subject capitalization, according to research by Boomerang.