You've probably received a bunch of emails from companies telling you that they're changing their privacy policies, and perhaps asking you for permission to keep sending you email.

And, if you're like most Americans, those emails went straight into the trash.

This is causing a nightmare for companies that rely on email newsletters or offers to gain and retain customers. The email marketing industry is projected to be worth $22.16 billion worldwide by 2025, according to Transparency Market Research, and approximately 82 percent of companies use email marketing, per marketing research firm Ascend2.

"People are not opting back in," says Michael Horn, the director of data science for digital marketing agency Huge. "It's one thing for your customers who don't have a relationship with the brand to decline and not respond, but you're also losing a sales channel."

Internal research from Huge found about 38 percent of Americans are ignoring these emails, and 23 percent have actually used them as an opportunity to unsubscribe. Email marketing firm PostUp has even grimmer stats, estimating that only 25 to 30 percent of recipients globally, and only 15 to 20 percent in the U.S., are opening the emails at all.



"An email that says 'privacy policy updates' is never going to get opened," says PostUp vice president of marketing and product Keith Sibson. "You never read the terms and conditions when you sign up for some website. It depends a lot on how it's being presented to the users and how important the sender is making it sound."

One email marketing firm said some of its clients have lost 80 percent of their email audience because they couldn't get customers to open those emails and say it was OK to keep sending them email. This company asked for anonymity because of confidentiality agreements with its clients.