Apparently you should never include this in a work email

Whether you have 4,260 unread emails or your inbox is always clear, there are some question marks when it comes to professional communication. How friendly is too friendly? Is it ever appropriate to leave a 'x'? And what's the done thing when it comes to emojis?

Well, research published in the journal Social Psychological and Personality Science revealed that using smiley faces in professional emails could actually result in your colleagues thinking less of you. The study by Amsterdam University, Ben-Gurion University of the Negev (BGU) and the University of Haifa asked 500 participants from 29 countries to undertake some everyday work tasks, one of which was assessing emails from strangers - some with emojis, some without - to determine what we really think about including them.

While you might think that emojis make an email more lighthearted and friendly, participants deemed those who used them to be less competent.

Author of the study, Dr Ella Glikson, told Stylist it could be detrimental to your professional reputation.

'Our findings provide first-time evidence that, contrary to actual smiles, smileys do not increase perceptions of warmth and actually decrease perceptions of competence,' she said.

'The study also found that when the participants were asked to respond to emails on formal matters, their answers were more detailed and they included more content-related information when the email did not include a smiley.'

As part of the research, individuals were also asked to rate emails that included a photograph of the sender attached, either a smiling or neutral. Those who looked happy scored highest in terms of competence and friendliness. But as the study was based on correspondence between strangers, if you're guilty of sending your colleague a smiley every so often you probably don't have much to worry about.

She continued: 'A smiley can only replace a smile when you already know the other person. In initial interactions, it is better to avoid using smileys, regardless of age or gender.'

However, if you're introducing yourself to the team via email, probably best to leave the emojis out.