Email Security Best Practices for Businesses: A Complete Guide to Protect Your Organization

By admin

Email is one of the most crucial forms of communication between businesses and their clients, suppliers, staff, and other partners at the global level. As such, email forms the basis of day-to-day operations for any company, as each time a company conducts business, email will be used to facilitate many, if not all, of those transactions. 

Just one compromised email account can lead to companies suffering losses that can result from regulatory penalties, financial losses, data breaches, ransomware attacks, and irreparable damage to the company’s reputation.

With businesses continuing to utilize cloud-based email products such as Microsoft 365 and Google Workspace, implementing strong email security processes is no longer optional—it is now essential.

This email security best practice guide will cover the best email security practices companies should implement to protect sensitive data, ensure compliance with regulations, and build trust with customers.

Table of Contents

Why Email Security Is Important

Businesses use emails to send thousands of different types of sensitive information, such as:

  • Client Data
  • Financial Information
  • Contracts
  • Employee Data
  • Intellectual Property
  • Usernames/Passwords
  • Business Proposals
  • Payment Instructions

Without proper protection from attack, email systems can be used by an attacker for:

  • Stealing Confidential Data
  • Ransomware Attacks
  • Business Email Compromise (BEC)
  • Financial Fraud
  • Spreading Malware
  • Damaging Brand Reputation

So the good news is that having good email security reduces these types of risks significantly.

Common Email Security Threats
Once you have identified the types of threats, you can begin to take steps to protect your organization from them.

1. Phishing Emails

Phishing Emails are sent by attackers pretending to be legitimate companies in order to obtain someone’s password, banking information, or other private business information without them realizing it was obtained illegally. Examples of Phishing Emails include:

Phony Microsoft login pages
Phony invoice emails
Emails asking to reset passwords
Emails asking for tax refunds

2. Business Email Compromise

A common type of attack is to impersonate an executive or the person that handles finance within a company via spoofed email. Examples of these attacks could be if an attacker:

Pretends to be a company’s CEO
Asks a company’s finance department for an immediate wire transfer
Asks a company’s finance department to change a vendor’s existing payment information
Has stolen payroll information

These attacks cause billions of dollars in losses each year.

3. Infected Attachments

Emails may contain:
Infected PDF Files
Word Documents with Macros
Excel Files
ZIP File Archives
Executable File Types

When opened, these types of file can install ransomware or spyware.

4. Credential Theft

Attackers will create fake login pages that appear to be legitimate versions of Microsoft 365, GMail, Dropbox, SharePoint, and/or Banking Portals; thus when an employee enters their credentials, the attacker will now have that employee’s credentials.

5. Spoofed Emails

Attackers can send spoofed emails that appear to be from someone that the recipient knows and trusts. Without authentication protocols, an attacker can impersonate a company executive, HR, Finance, or a business partner.

Best Email Security Practices for Businesses
1. Use Multi-Factor Authentication (MFA)
MFA is required for all employees, as passwords are no longer secure enough.
Consider MFA benefits:
Prevention of unauthorized access
Protection of stolen passwords
Adding a second verification layer
Reducing account takeover chances


Common methods of Authentication:

Using a mobile app to authenticate
Hardware security keys
SMS – A less preferred method of verification, however, much better than nothing


2. Enforce Good Password Policy
Encourage employees to have:

Unique Passwords
Long and complex passwords
Password’s should always be strored logs in a password management software


3. Enable SPF DKIM and DMARC

Email Authentication Protects your domain from Email Spoofing
SPF is a sender policy framework
Specifies which email servers are authorized to send email on behalf of your domain
DKIM Provides Digital Signatures for outgoing email messages
DMARC (Domain-based Message Authentication, Reporting & Conformance) 


Aligns SPF and DKIM while also offering reporting and enforcement functions.


Advantages are: 


prevention of spoofing. 


Decreased chances of being phished.


Improved delivery of email. 


Protection of brand reputation.