Once your email reaches your customers' email inbox safely, 2 factors are critical for the open rate of your email marketing campaign:

1. Sender's Name: Do your recipients know you? Emails with a known sender would be much more likely to be opened. When customers signed up your email newsletter, have you made it clearly that from whom they were expecting to get an email?

2. Email Subject: If you were the customers, would you open it? Is it easy to understand? Is it attractive enough? It works much better if you could customize the email subject to each of your recipient. It makes people feel respected.

Go ahead and make changes, and you'll see your email campaign open rate improve!