That’s what email automation firm Yesware did. Email Subject Lines That Actually Work, its recent ebook, shares what works (shorter subject lines) and what doesn’t (subject lines framed as questions). Some of the more surprising findings: emails that look like forwards (with “FWD:” or “RE:” in the title) get opened more, although less so on mobile devices, and putting numbers in your subject line gives you a slight advantage.
Some of the lessons are what you’d expect. Lay off the exclamation points! Don’t pretend to know someone when you don’t. Never use the term “appropriate person.” And no, people don’t want to join your webinar. Yes, Yesware published this because it wants to sell you software, and you have to give up your email address for the PDF. But the tips here will be useful to you even if you don’t ever want to try the company’s product.