Email, due to its widespread use, is currently the most common way cyber criminals launch and distribute threats, such as phishing, ransomware or spoofing. Email is also a common entry point for attackers looking to gain a foothold in your network to steal valuable company data. As such, the objective of email security is to minimize the likelihood of those threats from entering your company.
Ensuring your email environment remains safe, requires security activities on different fronts. An important technical control is to have an up-to-date antimalware and anti-virus protection. Also, the end-users should be regularly trained/reminded on the risk by planning regular reoccurring “awareness sessions” for all levels of end users. They should remain vigilant when clicking on links embedded in the emails or when opening attachments and to come forward in case the user noted something peculiar.
Furthermore the IT team can secure its mail infrastructure by implementing security measures like SPF, DKIM and DMARC. SPF, for Sender Policy Framework will limit which SMTP servers are allowed to send email on behalf of your domain. DKIM, for Domain keys Identified Mail, is used to sign mails with unique signatures. DMARC, for Domain based Message Authentication Reporting and Conformance, is used to enforce email policies regarding your domain.
Finally your service should be able to send and receive emails using TLS (Transport Layer Security).