Popular email clients such as Outlook and Apple Mail show a short preview of the email text under the subject line. In BoltMail we call this the "Preheader" and you can set this text on the Setup step when creating or editing an email campaign. Always have some interesting content here to draw your subscribers interest. You can also personalise this text using all of the usual merge tags such as [FNAME] and [LNAME]. See Campaign tags and filters
Much of the advice we suggest for subject lines applies here too, see Increase your email open rate by improving your subject lines
If you do not set any text here then browsers will display the first line or so of text from the email itself, often this is not what you want since most email templates include a link to view the web version of the email at the top, so recipients might see something like "View this email in your browser" which is not very enticing!
