The purpose of this paper is to investigate the behaviour response of computer users when either phishing e‐mails or genuine e‐mails arrive in their inbox. The paper describes how this research was conducted and presents and discusses the findings. This study was a scenario‐based role‐play experiment that involved the development of a web‐based questionnaire that was only accessible by invited participants when they attended a one‐hour, facilitated session in a computer laboratory. The findings indicate that overall, genuine e‐mails were managed better than phishing e‐mails. However, informed participants managed phishing e‐mails better than not‐informed participants. Other findings show how familiarity with computers, cognitive impulsivity and personality traits affect behavioural responses to both types of e‐mail. This study does not claim to evaluate actual susceptibility to phishing emails. The subjects were University students and therefore the conclusions are not necessarily representative of the general population of e‐mail users. The outcomes of this research would assist management in their endeavours to improve computer user behaviour and, as a result, help to mitigate risks to their organisational information systems. The literature review indicates that this paper addresses a genuine gap in the research.