Some people enjoy seeing a small emoji in a subject line because it feels friendly and easy on the eyes. It can make the email stand out when the inbox is crowded. At the same time, certain readers see emojis as childish, especially if they expect a more serious tone. The best way is to think about who usually reads your emails. A light audience may enjoy them, while a business group may prefer plain text. Using one simple emoji is usually safe, but adding too many can look messy. Trying both styles on a small group can show what feels natural. Do you feel emojis add charm to a subject line or make it look unnecessary?