Microsoft 365 and Google Workspace are where modern businesses work. But should your productivity platform also be the only security layer protecting your email?
Microsoft 365 and Google Workspace both provide capable native email security. However, organisations with higher security requirements often need an additional, independent layer of protection.
That is where Mimecast Email Security can add significant value.
Mimecast Email Security is designed to help organisations strengthen protection against phishing, business email compromise, malicious links, dangerous attachments, impersonation, data loss and email downtime.
Rather than replacing Microsoft 365 or Google Workspace, Mimecast Email Security can work alongside them to create a stronger defence-in-depth approach.
Why Mimecast Email Security Matters
Email remains one of the most common ways attackers target organisations.
A single malicious email can:
- Steal Microsoft 365 or Google Workspace credentials
- Trick an employee into approving a fraudulent payment
- Deliver malware or ransomware
- Impersonate an executive or supplier
- Expose confidential information
- Give attackers access to sensitive business systems
The challenge is that modern email attacks are becoming increasingly difficult to identify.
Many attacks do not contain obvious malware. Instead, attackers use social engineering, legitimate compromised accounts, lookalike domains and carefully written messages designed to appear trustworthy.
This is why businesses increasingly require Mimecast Email Security as an additional specialist layer around their existing email environment.
1. Mimecast Email Security Adds an Independent Layer of Protection
One of the biggest advantages of Mimecast Email Security is independence.
In a traditional secure email gateway deployment, Mimecast can inspect messages before they reach Microsoft 365 or Google Workspace.
This means an inbound email may be analysed by Mimecast before it reaches the organisation’s native email-security controls.
Your organisation therefore benefits from multiple security layers.
Instead of relying entirely on a single security engine, you introduce another platform with its own:
- Threat intelligence
- Detection technologies
- Security policies
- URL analysis
- Attachment inspection
- Impersonation protection
- Email-security telemetry
This creates a stronger defence-in-depth email security strategy.
If one security control misses a threat, another layer still has an opportunity to detect it.
2. Mimecast Email Security Helps Prevent Business Email Compromise
Some of the most damaging email attacks contain no malware at all.
Consider a message that appears to come from a senior executive:
“Please process this payment urgently. I am in meetings, so please do not call.”
There may be no malicious attachment and no suspicious URL.
The attacker is simply relying on trust.
This type of attack is known as Business Email Compromise, or BEC.
Mimecast Email Security provides impersonation-protection capabilities designed to identify suspicious characteristics such as:
- Display-name spoofing
- Lookalike domains
- Reply-to mismatches
- Suspicious sender behaviour
- Social-engineering indicators
- Executive impersonation attempts
This is particularly important for finance, procurement, HR and executive teams.
For these departments, email security needs to understand more than malware.
It needs to understand context.
3. Mimecast Email Security Protects Users Against Malicious Links
Phishing attacks frequently use links designed to steal employee credentials.
Attackers can also modify websites after an email has already been delivered.
A link that appears safe when an email arrives may later redirect users to a malicious login page.
Mimecast Email Security includes URL protection capabilities that can evaluate links when users interact with them.
This provides another opportunity to detect malicious websites before employees submit usernames, passwords or other sensitive information.
For organisations using Microsoft 365, this can be particularly important because compromised credentials may potentially expose access to:
- Outlook
- OneDrive
- SharePoint
- Teams
- Business contacts
- Documents
- Historical email
Protecting the user before credentials are stolen therefore becomes an important part of the organisation’s overall security strategy.
4. Mimecast Email Security Provides Advanced Attachment Protection
Traditional antivirus systems are effective against many known threats.
However, attackers continuously develop new malware variants designed to avoid signature-based detection.
Mimecast Email Security can analyse suspicious attachments before users interact with them.
Sandboxing technology allows potentially dangerous files to be inspected in an isolated environment.
Instead of asking only:
“Have we seen this malicious file before?”
the security system can also determine:
“What happens when this file is opened?”
This provides another layer of protection against previously unknown or modified malware.
5. Mimecast Email Security Works with Microsoft 365 and Google Workspace
A major benefit of Mimecast Email Security is that businesses do not need to replace their productivity platforms.
Employees can continue using:
- Microsoft Outlook
- Microsoft 365
- Exchange Online
- Gmail
- Google Workspace
Mimecast simply becomes another security layer around the existing environment.
A Microsoft 365 security architecture might therefore include:
Microsoft 365 + Microsoft Defender + Mimecast Email Security + Endpoint Security + SOC Monitoring
The objective is not to choose between Microsoft and Mimecast.
The objective is to use multiple complementary security controls.
6. Mimecast Email Security Helps Prevent Data Loss
Email security is not only about stopping threats coming into your organisation.
Businesses also need to protect sensitive information leaving the organisation.
Employees may accidentally email:
- Customer information
- Banking details
- Identity numbers
- Confidential contracts
- Employee records
- Financial documents
- Intellectual property
to the wrong recipient.
Mimecast Email Security can support outbound content controls and data-loss-prevention policies designed to identify sensitive information before it leaves the organisation.
Policies can be configured for different departments.
Finance
Protect banking and payment information.
Human Resources
Protect employee and personal information.
Legal
Control confidential contracts and legal documents.
Executive Management
Apply enhanced controls to sensitive executive communication.
For organisations operating under POPIA and similar data-protection regulations, these controls can form an important part of a broader information-protection strategy.
7. Mimecast Email Security Can Improve Email Continuity
Cybersecurity is not only about preventing attacks.
It is also about maintaining availability.
If your primary email platform becomes unavailable, the impact can quickly affect:
- Customer communication
- Supplier engagement
- Procurement
- Sales
- Support
- Internal operations
Mimecast provides email-continuity capabilities designed to help organisations continue communicating during certain disruptions to their primary email environment.
This allows organisations to think beyond simply blocking phishing.
It helps support a broader email-resilience strategy.
8. Mimecast Email Security Can Support Email Archiving
Email is often an important business record.
Historical messages may be needed for:
- Audits
- Investigations
- Legal matters
- HR disputes
- Regulatory enquiries
- Compliance requirements
- Cybersecurity investigations
Mimecast provides cloud email-archiving capabilities that can give organisations an additional layer of separation between their production email platform and retained email records.
For regulated industries, this can be particularly valuable.
9. Mimecast Email Security Helps Protect Your Brand
Attackers do not always target your employees.
They may impersonate your organisation instead.
For example, criminals may register lookalike domains resembling your legitimate domain and use them to target customers or suppliers.
A fake domain may appear as:
yourcompany-payments.com
yourcompany-support.com
or a subtle misspelling of your real domain.
Strong email protection should therefore include technologies such as:
- SPF
- DKIM
- DMARC
- Domain monitoring
- Impersonation protection
This helps protect not only your employees but also the reputation associated with your organisation’s brand.
10. Mimecast Email Security Gives Security Teams Better Visibility
When a phishing campaign occurs, security teams need to understand the full scope of the attack.
They may need to know:
- Who received the message?
- Who clicked the link?
- Were multiple users targeted?
- Was an executive impersonated?
- Are similar messages still circulating?
- Has the malicious email been removed?
Mimecast Email Security can provide additional security telemetry that can contribute to a broader cybersecurity monitoring strategy.
For organisations using a SOC, SIEM or managed security service, email events can potentially be correlated with:
- Endpoint events
- Authentication activity
- Firewall logs
- Identity events
- Cloud activity
- Network behaviour
This transforms email from an isolated security system into another valuable source of cybersecurity intelligence.
Mimecast Email Security vs Native Microsoft 365 and Google Workspace Security
Microsoft 365 and Google Workspace both include important email-security capabilities.
The value of Mimecast is therefore not based on replacing those controls.
It is about strengthening them.
| Security Requirement | Native Platform Security | Mimecast Email Security |
|---|---|---|
| Spam filtering | Yes | Yes |
| Malware protection | Yes | Yes |
| Phishing protection | Yes | Additional independent layer |
| URL protection | Available | Additional URL protection layer |
| Attachment inspection | Available | Additional sandboxing layer |
| BEC and impersonation protection | Available depending on licensing | Dedicated capabilities |
| Outbound email controls | Available depending on licensing | Dedicated email-security policies |
| Email continuity | Platform dependent | Dedicated continuity capability |
| Email archiving | Available within ecosystem | Independent archiving option |
| Email threat visibility | Native telemetry | Additional email-security telemetry |
The strongest approach is often not:
Microsoft 365 or Mimecast.
It is:
Microsoft 365 and Mimecast Email Security.
The same principle applies to Google Workspace.
The Real Advantage of Mimecast Email Security
The value of Mimecast Email Security comes from the combination of four important areas.
Specialisation
Mimecast focuses heavily on messaging, collaboration and human-risk security.
Independence
It provides another security layer outside your primary productivity environment.
Defence in Depth
An attacker that bypasses one security control still needs to bypass another.
Resilience
Security, continuity and archiving can form part of the same broader email-security strategy.
Who Should Consider Mimecast Email Security?
Mimecast Email Security is particularly relevant for organisations that:
- Process invoices and payments through email
- Handle sensitive or regulated information
- Have executives regularly targeted by phishing
- Work with large numbers of suppliers
- Operate in banking, insurance, government, healthcare, legal or telecommunications
- Have experienced phishing or business email compromise
- Require stronger data-loss-prevention controls
- Need email continuity
- Require independent email archiving
- Operate a SOC or managed cybersecurity service
For these organisations, email is not simply a productivity tool.
It is a critical cybersecurity control point.
Strengthen Your Email Environment with Mimecast Email Security
Microsoft 365 and Google Workspace remain excellent productivity platforms.
There is no need to replace them.
The goal is to protect them more effectively.
By introducing Mimecast Email Security, organisations can add another layer of protection against phishing, business email compromise, malicious links, dangerous attachments, impersonation and data loss.
At Prima Secure, we help organisations deploy, configure and manage Mimecast Email Security alongside existing Microsoft 365 and Google Workspace environments.
Our services include:
- Mimecast Email Security deployment
- Microsoft 365 integration
- Google Workspace integration
- Email-security policy configuration
- Business Email Compromise protection
- Impersonation protection
- URL and attachment protection
- Data-loss-prevention policies
- Email continuity
- Email archiving
- SPF, DKIM and DMARC configuration
- SOC integration and monitoring
Our approach is simple:
Use the technology you already have, strengthen the gaps and add additional security where it delivers real value.
Already using Microsoft 365 or Google Workspace?
Speak to Prima Secure about an Security assessment and discover how an additional security layer can strengthen your organisation’s environment.