<ul data-eligibleForWebStory="false">Vogue editor Anna Wintour is known for occasionally sending emails without subject lines.Comedian Alison Leiby received an email from Anna Wintour with no subject, causing initial stress.Despite the anxiety, Leiby described the email as 'the best email of my life,' after it turned out to be positive.Experts recommend including subject lines in business communications to provide clarity and help recipients prioritize messages.