The modern workplace has moved beyond the office. Unfortunately, cybercriminals have followed.
With employees logging in remotely across the globe, business communications have become a leading attack vector. In fact, the Anti-Phishing Working Group (APWG) reported more than 1 million phishing attacks in the first quarter of 2025, the most reported since late 2023. Email now accounts for the majority of initial compromise attempts, making advanced protection an operational necessity for IT teams.
Traditional perimeter-based defenses weren’t built for today’s distributed teams. Cloud email security solutions, by contrast, offer scalable, AI-driven protection against common threats like phishing, business email compromise (BEC), and ransomware.
In this guide, we’ll look at what makes cloud email security a must-have for keeping business communications safe in our rapidly changing threat landscape.
Key takeaways
- Billions of malicious emails are sent daily, making cloud email security essential to protect remote and hybrid teams from constant attack.
- Cloud-based email security solutions provide real-time, AI and machine learning (ML)-driven defenses that help block phishing, ransomware, and business email compromise.
- Data loss prevention (DLP), outbound filtering, and continuity features like emergency inboxes and instant replay help protect sensitive data and maintain communication during outages.
- Centralized dashboards (such as the ConnectWise Security Dashboard in Asio) give IT teams one pane of glass for monitoring threats across distributed users and environments.
- Even with advanced tools, human error remains the biggest risk. Ongoing employee security awareness training is one of the most effective measures for email security.
What is cloud email security?
At its core, cloud-based email security protects email data by filtering out spam and malware before they ever reach a user’s inbox. Unlike on-premises solutions that rely on localized servers and manual updates, cloud email security solutions leverage the scalability of the cloud to provide always-on, real-time protection ideal for distributed and remote workforces.
These solutions work by:
- Filtering malicious content such as spam, malware, and suspicious attachments.
- Detecting impersonation attempts like domain spoofing and executive fraud.
- Blocking zero-day threats (previously unknown vulnerabilities with no available patch) using AI and machine learning that identify abnormal behavior before known signatures exist.
Because protection runs in the cloud, new threats can be identified and mitigated globally in near real time. That means businesses aren’t relying solely on static signatures or delayed patching. The defense evolves at the speed of cyberthreats, keeping remote teams secure wherever they log in.
Cloud email vs. on-premise
Organizations still debate whether to secure email with on-premises systems or cloud-based services.
On-premises email security typically relies on hardware appliances or servers managed in-house. While this provides direct oversight, it has significant drawbacks, like limited scalability and heavy IT resource requirements. These limitations can leave dangerous security gaps as teams shift to remote and hybrid work.
Cloud email security flips that model, delivering flexible and continuously updated protection. Threat intelligence is updated and shared globally in real time, giving IT teams immediate defenses against emerging tactics like phishing and BEC.
Cloud solutions also scale easily, delivering consistent protection across devices and locations, without the management overhead of hardware.
Cloud email security features
A strong cloud-based email protection solution goes beyond spam filtering. The right solution provides multiple layers of defense to help stop threats at every stage of the attack chain. Cloud email security solutions are often offered in multiple service tiers to meet different organizational needs. Some include only essential protections, while others provide advanced threat detection and continuity features.
Some key features to look for include:
- Core protection: Blocking spam and malicious content through connection-level email address reputation checks and custom content filtering.
- Advanced threat protection: Includes tools such as click-time URL sandboxing and predictive URL defense that detect malicious links based on behavior at the time of interaction, rather than static blacklists.
- Business email compromise defense: AI-driven detection of impersonation attempts that trick employees into transferring money or disclosing sensitive information.
- Outbound email protection: Uses content filtering and data loss prevention (DLP) to help prevent sensitive or regulated data from leaving the organization through email.
- Continuity services: Features such as spooling, instant replay, and emergency inboxes help ensure ongoing communication even during disruptions to the primary email server.
- Visibility and reporting tools: Built-in dashboards and logging provide IT teams with a clear view of email-based threats across environments, helping streamline monitoring and compliance.
Why cloud email security matters
Remote and hybrid work have widened the attack surface. Employees connecting from home networks, mobile devices, and public Wi-Fi give attackers more ways to exploit weak points. And email remains an easy way in.
Some of the most common threats targeting remote teams include:
- Phishing: Deceptive spam and phishing emails are designed to trick users into clicking malicious links or sharing credentials. Cybersecurity awareness training helps, but advanced detection is critical since attackers often play on emotion and urgency, making even trained users more likely to click.
- Business email compromise: These sophisticated impersonation attacks target employees with fraudulent payment requests or sensitive data transfers. These scams cost businesses billions each year.
- Malicious software: Malware and ransomware involve malicious attachments and links that lock down systems or exfiltrate sensitive information, causing costly downtime and data loss.
Beyond threat defense, cloud email security solutions offer several benefits:
- Scalability for distributed teams across locations and devices. Add or remove users quickly and efficiently as team members join or leave your clients’ organizations.
- AI and machine learning to keep pace with evolving threats in real time and intelligently filter spam and phishing attempts.
- Centralized visibility through tools like unified dashboards that give admins a single view of email threats across environments, reducing the need to juggle multiple tools.
Integration with platforms like Microsoft 365 and directory services helps simplify deployment and ensures protection is consistently applied across users and locations. In addition, real-time reporting tools and support for security information and event management (SIEM) systems enable greater visibility and control for IT teams.
Common cloud email security challenges
While cloud email security provides significant advantages, IT teams still face challenges that highlight the need for careful planning and the right technology partner:
- Misconfigurations: Simple setup errors, like weak permissions or disabled encryption, can expose mailboxes and shared files to attackers. Even minor oversights create significant risks.
- Identity and access management (IAM) challenges: IAM defines an organization’s security permissions and user roles. Weak IAM procedures, such as not using multi-factor authentication or failing to enforce zero trust or least privilege principles, can open your system to unauthorized access.
- Regulatory compliance: Cybersecurity regulations such as the Health Insurance Portability and Accountability Act (HIPAA) or General Data Protection Regulation (GDPR) require strict data handling. Misconfigured controls or poor visibility in the cloud make demonstrating compliance far more difficult. DLP and encryption tools can help reduce risk by automatically scanning outgoing messages and applying data protection policies where needed.
- Application programming interface (API) security: APIs connect cloud email systems with other SaaS applications, but weak controls can create serious risk. Common threats include OAuth token abuse, misconfigured API permissions, and SaaS-to-SaaS trust exploitation.
- Business email compromise: Even with filtering in place, BEC remains a costly threat. Attackers refine impersonation tactics constantly, and are now using AI to draft believable emails and invoices at scale, even across different languages. Defending against the dynamic nature and unlimited scalability of generative AI will require sophisticated—and unprecedented—security solutions.
Addressing these challenges requires more than a single layer of defense. It calls for an integrated, multi-pronged approach that combines advanced detection, proactive monitoring, and ongoing user education.
Best practices for cloud email security
Securing email in today’s remote-first environment requires a layered strategy that combines technology and people. Here are some best practices for IT teams to adopt:
- Enable multi-factor authentication: MFA adds a critical layer of security beyond passwords, making it harder for attackers to exploit stolen credentials.
- Invest in employee training: Many data breaches involve human error. Continuous user education on spotting phishing and social engineering attacks is your first line of defense in keeping cloud email safe. Train your team on the most common phishing attacks, socialize phishing prevention tips, and occasionally run phishing tests to reveal gaps before attackers do.
- Leverage AI and machine learning: Threats evolve too quickly for manual defenses. Cloud-based solutions powered by AI and ML can analyze patterns and detect suspicious activity in real time, preventing many phishing attacks before they start.
- Implement encryption: Protect sensitive information at rest and in transit to maintain compliance and safeguard customer trust.
- Adopt a unified security strategy: Consolidating threat detection and visibility into a single interface reduces complexity, particularly for IT teams managing multiple environments. Choosing a solution with tiered options can also help align protection levels to organizational needs.
Want to see how these best practices come together in practice? Check out our webinar, A Unified Strategy for Email Security.
Key features to look for in a cloud-based email security service
A complete cloud email security service provides layered defenses that address phishing, ransomware, data loss, and account compromise. When evaluating options, IT teams should look for capabilities that protect inbound and outbound messages, minimize downtime, and improve visibility across distributed teams, including:
- AI- and ML-powered threat detection
- Click-time URL sandboxing
- Predictive URL defense
- Business continuity features (emergency inbox, spooling, instant replay)
- DLP and outbound content filtering
- Integration with Microsoft 365 and directory services
- SIEM-compatible reporting and alerting tools
Cloud email security is not one-size-fits-all. That’s why ConnectWise Email Security with Proofpoint offers multiple tiers of protection, including both essential safeguards and advanced threat detection. With support for Microsoft 365 integration, email continuity features, outbound protection, and centralized dashboard management via the ConnectWise Asio platform, IT teams can protect employee inboxes with confidence.
Don’t wait for an attack to test your defenses. Request a demo to see why ConnectWise Email Security is the solution IT teams are turning to for end-to-end email protection.
