The opening rate is the number of people who opened the email. A good average open rate is between 14.5 and 22%.
This rate may seem low but email users are often extremely solicited by email and receive dozens per day and do not open many.
To improve this rate, work on the subject of your newsletter. Indeed, it is generally the determining criterion of the opening of an email. It must appeal to your reader.
Your audience may also be more active and likely to open your email at certain times. Try different sending times in order to find the most relevant one.