When you’re sending an email to a colleague or a client, you might like to keep the tone light to build a friendly relationship.

However, a new study suggests you should be careful how casual you make your emails.

Researchers from BGU, University of Haifa, and Amsterdam University found that including emojis in work emails may make your colleagues think you are less competent, which can make them less likely to share information with you.

The researchers carried out a series of experiments with 549 participants from 29 different countries.

In one experiment participants were asked to read a work-related e-mail from a stranger and evaluate both the competence and warmth of that person.

The participants all received similar messages, but only some included smiley emojis.

"Our findings provide first-time evidence that, contrary to actual smiles, smileys do not increase perceptions of warmth and actually decrease perceptions of competence,"said Dr. Ella Glikson, a post-doctorate fellow at BGU's Department of Management. "In formal business e-mails, a smiley is not a smile."

The study also found that when participants were asked to reply to the work emails, less information was shared to the senders of the smileys.

The experiment also demonstrated a degree of sexism in the interpretation of the use of emojis.

When the gender of the sender was unknown, recipients were more likely to assume that the e-mail was sent by a woman if it included a smiley.

"People tend to assume that a smiley is a virtual smile, but the findings of this study show that in the case of the workplace, at least as far as initial 'encounters' are concerned, this is incorrect," Glikson said.

"For now, at least, 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."