Mimecast Advanced Email Security Reviews & Product Details

One thing I have appreciated about Mimecast Advanced Email Security is how effectively it catches phishing and impersonation attempts it flags look-alike domains and spoofed sender names before they reach the inbox, often with a clear warning banner. The time of click URL protection is also a nice touch, since it re-checks links even after delivery, catching malicious sites that go live later. On the admin side, the dashboard gives good visibility into threat trends and blocked emails, which has been useful for our IT team.

It integrates smoothly with our existing email setup without much disruption. The one downside is that it occasionally flags legitimate emails as suspicious, so there's a bit of a learning curve in fine-tuning the filters, but overall it's been a reliable layer of protection. Review collected by and hosted on G2.com.

Honestly my biggest complaint is the admin dashboard, it's kind of a lot to take in at first. Took me a while to figure out where everything was instead of just clicking around trying to find stuff. It connected fine with our Microsoft 365 setup, but a couple of the settings weren't as easy to line up as I thought they'd be. Sometimes a normal email gets delayed a few minutes because it's scanning it, which is annoying if you're waiting on something important.

It also flags emails as suspicious sometimes when there's nothing actually wrong with them, and it's not always clear why it did that. Support was fine when I reached out, but the onboarding kind of assumes you already know a bit about email security, so it wasn't super beginner friendly at first. And it's on the pricier side compared to other options, so that's something to think about if budget is tight. Review collected by and hosted on G2.com.

Honestly, it's how much it stops before I ever see it. Phishing and spoofed emails just don't make it through, and the link and attachment scanning has caught stuff that would've slipped past us otherwise. The admin side is simple too, easy to pull logs or release something from quarantine without digging around. Review collected by and hosted on G2.com.

The false positives are the main annoyance. Legit emails end up in quarantine more often than I'd like, so there's a bit of babysitting involved. The interface also feels dated in spots, and finding the right setting sometimes takes longer than it should. Nothing dealbreaking, just friction. Review collected by and hosted on G2.com.

I like Mimecast Advanced Email Security’s targeted threat protection, especially URL Protect’s real-time URL rewriting and click-time analysis, and Attachment Protect’s sandboxing and file analysis to block malicious links, credential-harvesting attempts, zero-day malware, and ransomware. I also value its impersonation protection, policy controls, and tools for journaling, archiving, e-discovery, and investigating reported phishing emails. The logs and dashboard help me trace delivery status and address issues. The initial setup was relatively straightforward, and the onboarding documentation and guided setup made it manageable. URL protection, attachment sandboxing, and impersonation defense give me confidence in stopping advanced phishing and day-to-day threats. Review collected by and hosted on G2.com.

I find URL Protect and Attachment Protect can be overly aggressive, blocking legitimate business links or delaying time-sensitive file deliveries. I have to keep fine-tuning bypass policies and help users handle blocked items without compromising security. The admin console has a steep learning curve, and managing overlapping policies and definitions across multiple domains can get complex and feel counterintuitive. URL rewriting can occasionally break specific web app integrations, and Mimecast warning pages on safe links can confuse users. Digging into older logs or exporting them to tools like Splunk or Microsoft Sentinel can also feel clunky compared with using those platforms directly. Review collected by and hosted on G2.com.

What I like most about Mimecast Advanced Email Security is its ability to protect organizations against phishing, malware, spam, and other email-based cyber threats. Its advanced threat detection, URL and attachment protection, and real-time security monitoring help reduce risks and improve overall email security. The centralized management and visibility also make it easier for security teams to identify and respond to suspicious activities. Review collected by and hosted on G2.com.

One area that could be improved is the user interface, as some advanced settings and configurations may take time for new users to understand. Additionally, occasional false positives may require manual review, and managing security policies can involve an initial learning curve. Overall, improving ease of use and simplifying configuration would make the product even better. Review collected by and hosted on G2.com.

I use Mimecast Advanced Email Security as our primary secure email gateway to protect our Microsoft 365 environment. Its targeted threat protection works exceptionally well against sophisticated phishing, domain spoofing, and zero-day malware before emails reach user inboxes. Real-time scanning and safe file conversions give our team peace of mind by defanging malicious links and weaponized files in transit. It reliably catches subtle executive impersonation that standard filters often miss. URL rewriting checks destination links when an employee clicks, helping prevent post-delivery web attacks, and safe file conversion blocks malicious files, weaponized PDFs, and macros before they reach user devices with minimal workflow interruption. Its core protection capabilities and threat visibility are top-notch. Review collected by and hosted on G2.com.

I find Mimecast Advanced Email Security could be easier to configure and manage, especially for teams handling a large volume of emails. The reporting could be clearer and policy settings more straightforward, and I’d like fewer false positives. When legitimate business emails are flagged, administrators have to review quarantine messages, verify they’re safe, and release them, which creates extra work and can delay business communication. Setting up and fine-tuning policies also takes time, and clearer documentation and better-organized configuration options would help. Review collected by and hosted on G2.com.

I like that Mimecast Advanced Email Security helps protect me from phishing, business email compromise, impersonation attacks, malware, and suspicious files. It also provides URL protection with link rewriting at the time of a click. I value its DMARC, SPF, and DKIM enforcement, message review and release workflows, and logs and reporting, which help with incident investigations, maintaining an incident register, and passing audits like ISO 27001. Our leadership is also very happy with it. The setup was easy, took around 1.5 days, and the guide helped me navigate the features. Review collected by and hosted on G2.com.

I think everything works well for me, and I don’t see any improvements required right now. I think Mimecast Advanced Email Security could increase protection when sandboxing suspicious files and add a real-time database for suspicious files and real-time display-name spoofing. Review collected by and hosted on G2.com.

I find Mimecast Advanced Email Security an efficient way to get communication out the door. It helps me send messages seamlessly and make sure the workflows, approvals, and testing are complete, so it’s an easy way to communicate. I also appreciate the governance and security around my communications. It helps keep my details compliant and my data, responses, and communications protected, without being shared with other vendors or companies without my permission. Review collected by and hosted on G2.com.

I think the UI could be a little bit better. I’d like the features and functionalities to feel more seamless for users, the toggles to be easier to switch back and forth, and the product to be as digestible for new users as possible. The product specifications and documentation on how to configure the tool for other companies seemed a little lacking. Review collected by and hosted on G2.com.

From a defensive engineering standpoint, Mimecast Advanced Email Security excels by neutralizing sophisticated attack vectors before inbox delivery while maintaining deep administrative visibility. Its strongest capability is dynamic time-of-click URL protection, which thwarts delayed-weaponization phishing where benign links turn malicious post-delivery. To combat payload-free business email compromise, its impersonation engine rigorously analyzes headers, display names, and domain similarity alongside strict SPF, DKIM, and DMARC alignment. For zero-day malware and weaponized macros, behavioral cloud sandboxing detonates attachments safely, with the option to instantly deliver flattened, read-only copies to eliminate operational delays. Crucially for SecOps teams, Mimecast avoids "black box" limitations: its policy engine enables granular, regex-driven routing controls, while rich REST APIs pipe threat telemetry directly into SIEM and SOAR platforms for automated cross-inbox clawbacks. The trade-off is console complexity, requiring proactive tuning to prevent third-party SaaS false positives. Review collected by and hosted on G2.com.

Mimecast’s primary drawbacks center on operational friction, interface complexity, and architectural overhead. Its administrative console is notoriously unintuitive, relying on a fragmented split between Definitions and Policies with rigid precedence rules that make troubleshooting routing or false positives cumbersome. Out of the box, aggressive anti-spoofing and impersonation checks frequently flag legitimate third-party SaaS senders like Salesforce or HubSpot, requiring constant administrative tuning. Furthermore, its time-of-click URL rewriting obscures true destinations, which confuses end users, breaks SSO redirects, and occasionally disrupts deep links. Because it fundamentally operates as a traditional secure email gateway requiring MX rerouting, securing internal-to-internal lateral movement demands separate configuration, while deep attachment sandboxing often introduces noticeable delivery latency during active workflows. Finally, the legacy Outlook add-in frequently causes stability and performance issues on endpoints, generating unnecessary help-desk tickets for already strained IT and security operations teams. Review collected by and hosted on G2.com.

I appreciate that Mimecast Advanced Email Security can be very granular to suit different environments. It gives administrators precise control over email policies, allowing us to configure custom routing, create specific bypasses, and adjust threat protection levels based on our organization's unique requirements without disrupting legitimate mail flow. Review collected by and hosted on G2.com.

While the high level of granularity is a major plus, it also means the administrative portal can be quite complex and overwhelming for new users. There is a relatively steep learning curve to understand exactly where all the different policies, definitions, and settings are located, which can make the initial setup and routine troubleshooting more time-consuming than necessary. Review collected by and hosted on G2.com.

1. Mimecast effectively blocks phishing, malware, ransomware, and BEC attacks before they reach user inboxes, improving overall email security.

2. The AI-driven threat intelligence helps identify suspicious emails, malicious URLs, and impersonation attempts with high accuracy.

3.The UI/UX is simple and intuitive, making it easy to monitor threats, manage policies, and review security incidents.

4. The seamless integration with Microsoft 365 helped us deploy and manage email security quickly without disrupting existing workflows.

5.Mimecast provides reliable and consistent performance, scanning emails efficiently while maintaining smooth email delivery and minimal impact on users.

6. The solution offers good value by reducing phishing incidents and minimizing the time spent on email threat investigations, delivering strong ROI.

7. The onboarding process was straightforward, and the support team has been responsive whenever technical guidance or troubleshooting was needed. Review collected by and hosted on G2.com.

The solution can be expensive for smaller organizations, particularly when additional modules and advanced features are required. Review collected by and hosted on G2.com.