We like the content filtering and secure messaging features.
Director, Information Services at Institute of Peace
We like the secure messaging features, but some aspects of the solution are annoying to users
Pros and Cons
- "We like the content filtering and secure messaging features."
- "Many of our users complain that the system is blocking too many attachments. It's a good practice from a security perspective, but our users think Mimecast is doing too much. It might be something we'll have to adjust."
What is most valuable?
What needs improvement?
Many of our users complain that the system is blocking too many attachments. It's a good practice from a security perspective, but our users think Mimecast is doing too much. It might be something we'll have to adjust.
For how long have I used the solution?
I have used Mimecast for about a year and a half.
What do I think about the scalability of the solution?
Mimecast is scalable. However, we did face some challenges with the secure messaging part.
Buyer's Guide
Mimecast Email Security
September 2025

Learn what your peers think about Mimecast Email Security. Get advice and tips from experienced pros sharing their opinions. Updated: September 2025.
868,787 professionals have used our research since 2012.
How was the initial setup?
I rate Mimecast seven out of 10 for ease of setup. Setting up Mimecast was pretty straightforward. We didn't need to deploy an on-prem client, so it was primarily configuring Mimecast to work with our mail flow. We had to switch over some of our domain services and ensure we had the proper certificates. It wasn't a difficult process. We also needed to communicate the changes to the staff and let people know how to access their blocked mail.
Only one person is required for the implementation, but a large enterprise might need a few admins to respond to user requests and release blocked emails.
What's my experience with pricing, setup cost, and licensing?
I rate Mimecast four out of 10 for pricing. I'm looking at value add for my organization. Since we made invested in the Microsoft enhanced security suite, Mimecast seems a little expensive relative to what we get from it. We already have phone functionality from another provider, so we only need Mimecast for secure messaging and email encryption. We think it's a bit expensive just for secured encrypted messaging.
Which other solutions did I evaluate?
We're an Office 365 customer, and we recently upgraded to the E5 license, which gave us many of the same security features as Mimecast, so we've started questioning if Mimecast provides a value add.
What other advice do I have?
I rate Mimecast Email Security seven out of 10. It's doing what it's supposed to do, but there are a few annoying things from a user perspective. For example, it requires you to enroll your device with Mimecast to open a link from a known sender. This is someone you know that you're messaging. If they add a link, you have to authenticate your device through multifactor authentication to follow the link in the email.
Which deployment model are you using for this solution?
Public Cloud
Disclosure: My company does not have a business relationship with this vendor other than being a customer.

Project Manager at TFG
The solution has good performance and excellent technical support
Pros and Cons
- "The solution's performance is good."
- "The solution is complex and not easy to use."
What is most valuable?
The solution's performance is good.
What needs improvement?
The solution is complex and not easy to use.
I have to continuously manage the tech in a different space with the solution. I've got to manage different types of rules separately.
For how long have I used the solution?
I have been working with Mimecast Email Security with Targeted Threat Protection for three years.
How are customer service and support?
The solution’s technical support is very good.
How would you rate customer service and support?
Positive
How was the initial setup?
The solution's initial setup requires a bit of additional consultancy. Mimecast manages things differently, and they have a country-based support framework. Since we have multinational customers and have instances in the UK and Australia, we've got to work through different support sectors.
What other advice do I have?
Mimecast could simplify the solution and include a central console like the one Microsoft has.
Overall, I rate the solution a nine out of ten.
Disclosure: My company does not have a business relationship with this vendor other than being a customer.
Buyer's Guide
Mimecast Email Security
September 2025

Learn what your peers think about Mimecast Email Security. Get advice and tips from experienced pros sharing their opinions. Updated: September 2025.
868,787 professionals have used our research since 2012.
IT Manager at a logistics company with 201-500 employees
Filters email messages for spam and phishing but needs to incorporate behavior-based analytics
Pros and Cons
- "The biggest advantage of Mimecast Email Security is its spam filtering. Its filtering feature is interesting."
- "The tool can be challenging because it relies on rule-based configurations, especially for addressing impersonation threats. This approach requires setting up numerous rules to ensure filtering. It should work based on behavior-based analytics."
What is our primary use case?
We use the tool for email security. It filters email messages for spam and phishing and provides overall security functions.
What is most valuable?
The biggest advantage of Mimecast Email Security is its spam filtering. Its filtering feature is interesting.
What needs improvement?
The tool can be challenging because it relies on rule-based configurations, especially for addressing impersonation threats. This approach requires setting up numerous rules to ensure filtering. It should work based on behavior-based analytics.
However, it relies on a database of blocked web addresses in the background rather than behavior-based scenarios. So, if a link is malicious and not in the database, it might slip through.
Based on my experience requesting changes and configurations, even simple security queries can sometimes be challenging. For instance, it took us a week to properly configure. Resolving the issue involved multiple rounds of testing and discussions via email and conference calls. So, I believe some aspects of maintenance and setup in Mimecast Email Security may not be as straightforward as expected.
For how long have I used the solution?
I have been working with the product since 2016.
What do I think about the stability of the solution?
The solution's stability depends on what's happening in the background. For instance, sometimes there's a delay in receiving emails, especially when waiting for MFA codes on web pages. Whether it's the product or something else causing this, I'm not sure.
How are customer service and support?
I haven't contacted the tool's support yet.
What's my experience with pricing, setup cost, and licensing?
We pay monthly fees to our provider.
What other advice do I have?
I rate the overall solution a seven out of ten.
Disclosure: My company does not have a business relationship with this vendor other than being a customer.
Head of IT & Innovation at Shoreham Port Authority
Though the tool needs to improve its stability, the setup phase is easy
Pros and Cons
- "The setup was easy."
- "I did have a problem with Mimecast. That is why I was looking for an alternative solution because their sender IP address gets poorly rated by Microsoft."
What is most valuable?
I really don't know all of the features of the solution.
What needs improvement?
I did have a problem with Mimecast. That is why I was looking for an alternative solution because their sender IP address gets poorly rated by Microsoft. So it blocks sending emails to Microsoft addresses. The aforesaid reason made me decide to opt for an alternate solution possibly.
For how long have I used the solution?
I have been using the latest version of Mimecast Email Security with Targeted Threat Protection for the last two to three years.
What do I think about the stability of the solution?
Stability-wise, I rate the solution a one out of ten because of its IP reputation.
What do I think about the scalability of the solution?
Scalability-wise, I rate the solution as six out of ten. With Mimecast's IP reputation being degraded by Microsoft, it just caused me huge problems.
How are customer service and support?
I rate the technical support one out of ten. The product is good. Mimecast's support is not the most flexible.
How would you rate customer service and support?
Negative
How was the initial setup?
On a scale of one to ten, where one is a difficult initial setup, and ten is easy, I rate the setup an eight. The setup was easy.
It was deployed in my organization through the cloud.
The deployment took two days.
The deployment was done by one person.
What's my experience with pricing, setup cost, and licensing?
On a scale of one to ten, where one is cheap, and ten is expensive, I rate the pricing a ten. It is an expensive tool, especially when compared to Microsoft Defender.
What other advice do I have?
The poor thing about Mimecast is due to their unwillingness to move our center IP to a different center IP. So it doesn't get a bad reputation with Microsoft, and they refused to do that. So that's why I would possibly end up choosing a different solution.
To those planning to use the tool, I would ask them to make sure they put you on an email server. However, it has got a bad IP reputation because it refused to move off to a different server.
Overall, I rate the solution a five out of ten.
Disclosure: My company does not have a business relationship with this vendor other than being a customer.
Tech manager at MKTech
Reliable, reasonably priced, and offers helpful support
Pros and Cons
- "The solution offers good technical support."
- "The installation is not so straightforward."
What is most valuable?
It's very stable.
We find the product to be scalable.
The solution offers good technical support.
The price is reasonable.
What needs improvement?
The installation is not so straightforward. In comparison, for example, Proofpoint or Defender offer easier installations when you integrate with Active Directory.
For how long have I used the solution?
I started using the solution five years ago.
What do I think about the stability of the solution?
The solution is stable and reliable. There are no bugs or glitches, and it doesn't crash or freeze.
What do I think about the scalability of the solution?
We can scale the solution as needed.
How are customer service and support?
Technical support is good. We are happy with the level of support on offer.
How would you rate customer service and support?
Positive
Which solution did I use previously and why did I switch?
I've used Defender, Proofpoint, and Mimecast.
Some companies are using Defender, some companies are using Proofpoint, and some are using Mimecast.
In my company, we are using Defender.
Mimecast and Microsoft Office 365 is better than Proofpoint for the mail filter rules only. The mail filter rules in Proofpoint are not the best.
How was the initial setup?
The solution is not straightforward to set up. The integration can be a bit harder than when compared to other solutions. That said, it's not so hard it's impossible.
I'd rate the initial setup a four out of five in terms of complexity.
What's my experience with pricing, setup cost, and licensing?
There are three types of licenses, however, I don't know the exact pricing or differences. My understanding is that it is not overly expensive, as my clients have used it for years and they would have left if it was costly.
What other advice do I have?
I'm a freelancer and working support for some companies who are using Mimecast and Proofpoint. Sometimes I create it as a subscription for them, and I configure everything from the scratch, and sometimes, I take it already configured and just maintain it and tune the settings in.
I'd advise those implementing the solution to read the documentation carefully before beginning.
I'd rate the solution eight out of ten. I'd rate them higher, however, they are difficult to set up with Active Directory.
Disclosure: My company has a business relationship with this vendor other than being a customer. Reseller/Implementer
Graduate Analyst at SecurityHQ
Can observe multiple information sensors and monitors outbound traffic
Pros and Cons
- "The initial setup is easy."
- "Mimecast need to ensure that the body text format is correctly handled and that images are properly embedded in the body text."
What is our primary use case?
We have a client using the Mimecast tool. We observe multiple information sensors, such as default information, mismatched data, unknown IPs, and various user activities.
They use Mimecast to monitor outbound traffic, including impersonation and mismatched data. All these activities are managed within Mimecast. Companies use Mimecast to enhance network security within their budget. For outbound communication, emails go to Mimecast, where they are scanned and delivered to the user.
What is most valuable?
We are monitoring emails that come from outside the organization. Some impersonation policies are in place, and we are tracking five different types of impersonation policies. These policies include external IP addresses, external users, reply-to mismatches, default inbound attachments, and VIP impersonation cases.
What needs improvement?
Mimecast need to ensure that the body text format is correctly handled and that images are properly embedded in the body text. Additionally, Mimecast should ensure that the system can accommodate multiple users and effectively send information to them.
For how long have I used the solution?
We are using V7.5.0 of the solution.
What do I think about the scalability of the solution?
One person is using this solution.
How was the initial setup?
The initial setup is easy.
What other advice do I have?
I have learned various aspects related to the topic. I will monitor all types of logs, including those from Mimecast, which provides information about users’ contacts, histories, and account numbers. Although multiple policies are in place, we are currently monitoring just five specific types.
Mimecast is useful. According to the premises, Mimecast is important, but the choice of tools often depends on each company’s requirements and budget. While Mimecast is a highly effective console for email protection, companies select tools based on their own budgets and needs.
It is easy for a beginner to learn. If a person understands impersonation policies and how to apply them, the process becomes straightforward. However, if someone is unfamiliar with these policies and their monitoring, it can be challenging. However, once a person is knowledgeable about impersonation policies, the process becomes much easier.
Overall, I rate the solution an eight out of ten.
Which deployment model are you using for this solution?
On-premises
Disclosure: My company does not have a business relationship with this vendor other than being a customer.
Information Technology Executive at IFS Africa
A stable solution that can be used for email security, but it should include more AI features
Pros and Cons
- "Email security is the most valuable feature of the solution."
- "The solution should include more AI features instead of Mimecast's more general static configuration tooling."
What is our primary use case?
We use the solution for email security.
What is most valuable?
Email security is the most valuable feature of the solution.
What needs improvement?
The solution should include more AI features instead of Mimecast's more general static configuration tooling.
For how long have I used the solution?
I have been using Mimecast Email Security with Targeted Threat Protection for two years.
What do I think about the stability of the solution?
I rate the solution a nine out of ten for stability.
What about the implementation team?
The solution was deployed by a vendor for us.
What other advice do I have?
Mimecast Email Security with Targeted Threat Protection is a well-known solution that was recommended to us by a third party.
I wouldn't say Mimecast Email Security with Targeted Threat Protection is the best tool out there, but it's okay. I would advise potential users to try out its alternatives as well.
Overall, I rate the solution a six or seven out of ten.
Which deployment model are you using for this solution?
Private Cloud
Disclosure: My company does not have a business relationship with this vendor other than being a customer.
Senior Head of IT at a construction company with 51-200 employees
The product is not scalable, and the features do not work properly, though URL inspection works pretty well
Pros and Cons
- "URL inspection works pretty well."
- "The attachment scanning feature doesn't work properly."
What is most valuable?
URL inspection works pretty well.
What needs improvement?
Nothing’s been working properly in the product. There's a lot of misclassification. The attachment scanning feature doesn't work properly.
The product needs to fix the existing problems, which Mimecast is always in denial about. It definitely must catch up with the market. It needs to fix its core products, which don't work very well.
For how long have I used the solution?
I have been using the solution for five years.
What do I think about the stability of the solution?
I rate the tool’s stability a four or five out of ten.
What do I think about the scalability of the solution?
The product is not scalable.
How are customer service and support?
The technical support is not great. It is poor at best.
How would you rate customer service and support?
Neutral
What was our ROI?
The return on investment and the value is very minimal with Mimecast.
What's my experience with pricing, setup cost, and licensing?
The price is fine. For what it is, the product is overpriced. It's pretty much in line with what we would expect. However, for what it does now, there are much better products.
Which other solutions did I evaluate?
I would definitely recommend Avanan over Mimecast. IRONSCALES is also good. However, Avanan is by far a much more developed and intelligent product. Avanan’s attachment scanning works flawlessly. It works very, very well. The accuracy for spam and phishing is far, far superior. It also has better visibility, reporting, and other built-in tools like Shadow IT. Avanan provides visibility of where people are logging in from. It helps with anomaly detection and account takeover. Overall, Avanan is a much better product.
What other advice do I have?
I don't know what happened to Mimecast, but it seems to be going backwards now. They've lost their way in the market, and other solutions are taking over now. I know a lot of people are having issues with Mimecast and are just moving away from it. Overall, I rate the solution a five out of ten.
Disclosure: My company does not have a business relationship with this vendor other than being a customer.

Buyer's Guide
Download our free Mimecast Email Security Report and get advice and tips from experienced pros
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Updated: September 2025
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