Email Open Rates
The email open rate is the percentage of newsletter recipients who actually open the mailing.
The problem with this important measure is that the email software usually measures the open rate with the help of a counting pixel. This means that an invisible 1x1 pixel image will be inserted into the email. As soon as this image is called, the software detects this call and evaluates the mail as open. Many e-mail programs (especially Outlook, but increasingly also Thunderbird and other programs) do not load pictures in emails or ask the recipient to unlock the pictures. Thus the counting pixel is not loaded and the mail can not be considered as opened, even if read by the recipient.
This means: especially in the B2B sector, where many recipients use Outlook, the email open rate is not really a reliable indicator anymore. In reality, the emails are read by more people than the opening rate indicates.
The opening rate is usually between 20 and 50%. Higher values are rare. A rate above 30% is commonly considered good.