If you're trying to appear as professional as possible in your work environment, it's best to leave emojis out of work emails.
The study says using emojis in work emails does not make you appear more friendly, and can actually make your co-workers see you as less competent.
“This negative perception of a person who uses smileys has also a negative effect on the willingness to share valuable information. Thus, it may have negative long-term consequences.”
Think twice before sending the smiley face emoji in a work email!