What is "preview text" in an email?
Preview text is one of the first things recipients see when an email reaches their inbox. It is displayed in the inbox after the subject line of an email and is usually pulled from the first line of text within the body of an email. If you do not specifically insert preview text, inboxes will automatically pull it from the first line of text within an email — this means that ALT text, your navigation bar, etc. could be pulled as the preview text. Accordingly, it's best to specify what exactly you want your preview text to display. You can insert preview text on the email preview screen (where your "From/Reply to" field is located) by entering it into the preview text input field.