Email is still one of the most common ways cyber criminals get into businesses.
The tactics may have changed, but the goal remains the same: trick someone into clicking a link, opening a file or sharing information they shouldn’t.
Today’s attacks are harder to spot than they used to be. Fake invoices look genuine, supplier impersonation scams are increasingly convincing and some attacks don’t even require a stolen password to succeed.
The good news is that effective email security doesn’t rely on a single tool. It’s about putting the right layers in place to reduce risk without making life harder for your team.
In this guide, we’ll walk through the controls that matter most, explain how they work together and share some practical steps you can take to strengthen your email security.
What Modern Email Security Looks Like
Good email security relies on multiple layers working together.
Some controls help prevent attackers from impersonating your organisation, while others scan links and attachments for malicious content. Additional layers monitor sign-ins, verify user identity and identify unusual activity.
When these controls work together, they significantly reduce the likelihood of a single mistake turning into a security incident.
Some of the most important layers include:
- Domain authentication using SPF, DKIM and DMARC to help prevent attackers from sending emails that appear to come from your organisation.
- Advanced email filtering to identify suspicious messages, malicious attachments and phishing attempts.
- Impersonation protection to detect lookalike domains and emails pretending to be suppliers, executives or trusted contacts.
- Safe link and attachment analysis to assess content before it reaches your users.
- Third-party app permission management to reduce the risk of unauthorised access through connected applications.
- Multi-factor authentication and Conditional Access to strengthen account security and reduce the impact of stolen credentials.
These controls significantly reduce risk, but people still play an important role. Regular cyber awareness training helps staff recognise suspicious activity and report concerns before they become larger issues.
DMARC and Protecting Your Business from Email Impersonation
Email impersonation remains one of the most common tactics used by cyber criminals. Attackers may attempt to send emails that appear to come from your organisation, a trusted supplier or a member of your leadership team.
Technologies such as DMARC (Domain-based Message Authentication, Reporting and Conformance) help verify whether emails are genuinely coming from the domains they claim to represent. When configured correctly, they make it significantly harder for attackers to impersonate your organisation and use your brand in fraudulent emails.
While these protections work behind the scenes, they play an important role in reducing email fraud and protecting your organisation’s reputation. Regular reviews help ensure they continue to work as intended as your business systems and email platforms evolve.
Protecting Against Modern Phishing Attacks
Phishing attacks have become more sophisticated over the last few years.
Attackers increasingly use QR codes and PDFs in emails to bypass traditional link scanning, create convincing emails using AI-generated content and hijack legitimate email conversations to appear more trustworthy.
Modern email security solutions help identify these threats by analysing sender reputation, scanning links and attachments, detecting suspicious behaviour and identifying attempts to impersonate trusted organisations.
Additional protections can also help detect lookalike domains. For example, an attacker may register a domain that closely resembles Microsoft or one of your suppliers in an attempt to trick users into trusting the message.
For finance teams, additional verification controls around payment changes and supplier banking details can provide another important layer of protection.
Keeping Third-Party App Access Under Control
Not every email-related security incident starts with a stolen password.
In some cases, users are tricked into granting access to a third-party application that appears legitimate. Once approved, that application may be able to access emails, files or other business data without requiring the user’s password again.
Reducing this risk starts with controlling who can approve applications and regularly reviewing what has access to your environment.
Some practical steps include:
- Requiring approval for applications requesting sensitive permissions.
- Reviewing connected applications on a regular basis.
- Removing unused or unnecessary integrations.
- Educating users to question unexpected permission requests.
These simple controls can significantly reduce the risk of unauthorised access through connected applications.
Making Multi-Factor Authentication Work Smarter
Multi-factor authentication (MFA) remains one of the most effective ways to protect business accounts.
The most effective MFA solutions balance security with usability. By reducing unnecessary prompts and applying additional checks only when risk increases, businesses can improve security without disrupting day-to-day work.
Modern Conditional Access policies allow organisations to apply additional checks only when risk levels increase. This might include logging in from a new location, using an unfamiliar device or attempting to access sensitive systems.
This approach strengthens security while keeping the day-to-day experience simple for staff.
Where possible, organisations should also consider phishing-resistant authentication methods such as passkeys or security keys, while disabling legacy authentication methods that bypass modern protections.
How Training and Monitoring Reduce Risk
Technology plays an important role in email security, but people remain a critical line of defence.
The most effective training programs are short, practical and based on real-world scenarios. Staff should feel confident identifying suspicious emails, verifying unusual requests and reporting concerns quickly.
Even with strong protections in place, some threats will inevitably make it through. That’s why visibility and monitoring remain such important parts of a layered security strategy.
Whether it’s a compromised account, unusual mailbox activity or an unauthorised application gaining access, identifying and responding to suspicious activity quickly can significantly reduce the impact on the business.
FAQs
Is email still the biggest cyber security risk for businesses?
For many organisations, yes. Email remains one of the most common ways cyber criminals gain access to systems, steal credentials and commit fraud.
What is the best email security solution?
There isn’t a single solution that stops every threat. Effective email security combines multiple layers including filtering, authentication, MFA, user awareness training and ongoing monitoring.
How can I tell if my email security is good enough?
A good starting point is checking whether MFA is enabled, DMARC is configured correctly, advanced filtering is in place and staff receive regular cyber awareness training. Regular reviews can help identify gaps before attackers do.
Can Microsoft 365 protect me from phishing emails?
Microsoft 365 includes strong built-in security capabilities, but most organisations benefit from additional configuration, monitoring and user training to reduce risk further.
Do small businesses need email security?
Absolutely. Small and medium-sized businesses are regularly targeted because attackers know they often have fewer dedicated security resources. Layered email protection can significantly reduce risk without creating unnecessary complexity.
How Ever Nimble Can Help
Email security has evolved well beyond spam filters and blocked attachments. Today’s threats target identities, exploit trust and often bypass traditional defences. A layered approach that combines preventative controls, user awareness and ongoing monitoring provides the strongest protection against modern attacks.
At Ever Nimble, we help organisations strengthen their email security through Microsoft 365 security controls, advanced email protection, cyber awareness training, managed SOC services and ongoing cyber security guidance.
If you’d like to understand how your current email security measures up, or identify opportunities to strengthen your defences, get in touch with our team.
