IT AI Index
Index Vendors › Mimecast Email Security · September 2026 Edition
Mimecast · 1 category · Ranked

Mimecast Email Security

125Judge labels
5First choices
32Negative labels
12 of 12Models named it
1Category
September 2026 Edition. Every number here is derived from the raw labels under vendor table vv2026-09.2, every buyer segment counted.
Best standing
7% in Email security for mid-market buyers
Rank 6 of 71 in the mid-market standingaccepted challenger
3 of 12 models made it the first choice on the direct prompt; 13% of its 45 labels there were negative.
By buyer segmentRead the same way at every buyer size.
In email security · each standing computed within its segment · bars are 0 to 100 · the accent bar is the product's own best reading

Standing by category

Every category where a model named Mimecast Email Security for a mid-market B2B company. Share is first choices across the direct, paraphrase, budget and scale prompts; rank is within every product named in that category.
CategoryFunctionShareRankNegative rateLabelsQuadrant
Email securitySecurity operations7%6 of 7113%45accepted challenger

Movement

This is the first edition on this tier, so no move can be computed for Mimecast Email Security yet. From the next edition this section shows, per buyer segment, whether its share moved by more than the measured noise floor.

By model

How each model treated Mimecast Email Security across every prompt where it was named for a mid-market B2B company. Twelve models, six prompts per category.
ModelFirst choiceAlternativeMentionNegativeLabels
Claude Haiku 4.501102
GPT-5.4 mini01203
Gemini 3.5 Flash02013
Perplexity Sonar10203
Grok 4.1 Fast23005
Mistral Small11215
DeepSeek V4 Flash02215
Llama 4 Maverick00101
Qwen 3.7 Flash12115
Kimi K202215
GLM 4.7 FlashX12216
MiniMax M2.502002

By framing

Which of the six questions produced the naming. By model says how often; this says asked what. The first-choice count on the right carries the marks of the models that produced it.
FramingLabels by classFirst choices
Direct26 labels4
Paraphrase16 labels1
Comparative32 labelsNone
Budget-constrained14 labelsNone
Scale-constrained16 labelsNone
Negative21 labels3not counted in share
First choiceAlternativeMentionNegative125 labels in all, every segment counted; 5 of the 8 first choices count toward share, since the comparative and negative framings do not. The bar is one segment per label class, to scale within the framing.

What the models said for it

Verbatim evidence the judge attached to positive labels.

“Mimecast is widely considered the leader in the mid-market segment because it solves three problems at once” GLM 4.7 FlashX · Email security · direct prompt · first choice
“Proofpoint or Mimecast edge out for most mid-market B2B due to balance of protection and usability” Grok 4.1 Fast · Email security · direct prompt · first choice
“Mimecast and Proofpoint are frequently cited as leaders for mid-sized businesses” Mistral Small · Email security · paraphrase prompt · first choice
“such as Microsoft Defender for Office 365, Proofpoint, Mimecast, or Netskope.” Qwen 3.7 Flash · Email security · negative prompt · first choice

And against it

Verbatim evidence attached to negative labels. A warning on a product with few labels is a warning; on a product with many, it is one voice among them.

“it has experienced security breaches in the past, including a certificate compromise... This has led some organizations to approach Mimecast with caution.” Mistral Small · Email security · negative prompt · soft negative
“Traditional SEGs (like legacy Proofpoint or Mimecast setups) require rerouting your MX records, which is complex to manage and can disrupt mail flow.” Gemini 3.5 Flash · Email security · paraphrase prompt · soft negative
“Be cautious with: Mimecast and Barracuda if you've had a past breach, or if you require immutable audit trails.” DeepSeek V4 Flash · Email security · negative prompt · soft negative
“Mimecast: The market leader. Very robust, excellent continuity... Can be pricey and interface-heavy.” Qwen 3.7 Flash · Email security · scale prompt · soft negative

Named alongside

The products named in the same answers as Mimecast Email Security, over the 125 answers that named it. Took the first choice instead counts the answers where the other product was the first choice and Mimecast Email Security was named but was not.
ProductSame answerTook the first choice insteadHead to head
Proofpoint Email Protection121 of 12525Not in the top three
Microsoft Defender for Office 365107 of 12541Not in the top three
Abnormal AI88 of 12515Not in the top three
Barracuda Email Protection54 of 1254Not in the top three
IRONSCALES51 of 12511Not in the top three
Check Point Harmony Email & Collaboration47 of 1253Not in the top three
Cisco Secure Email33 of 1250Not in the top three
Sublime Security19 of 1253Not in the top three
SpamTitan13 of 1252Not in the top three
Sophos Email13 of 1250Not in the top three
A head-to-head page exists where both products are in a category's top three. The other rows are the same fact without a page behind them, so they link to the product instead.

What carried it into the answer

The sites and pages cited by the answers that named Mimecast Email Security. A fact about retrieval, not a lever on the model.

Citations exist only for the models that return a source list, four of the twelve in this edition, so these counts come from 104 of the 125 answers that named Mimecast Email Security and are not a share of its labels.

Domains cited

gartner.com88
expertinsights.com46
sublime.security41
learn.g2.com40
proofpoint.com39
kaseya.com38
tech-insider.org36
cybervendorguide.com33
ironscales.com33
costbench.com25

419 of the 419 domain citations in answers naming Mimecast Email Security came from somebody else's page.

Pages cited

Pages are listed as the models cited them.

Names read as Mimecast Email Security

What the judge wrote, as written, with how often. The vendor table decides that these count as Mimecast Email Security; a claim can dispute any of them.
Mimecast 40Mimecast Advanced Email Security 3
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Claim this page

Claiming is free and changes nothing in the data. A claimed page shows a verified contact who is told when each edition publishes and when Mimecast Email Security's standing changes by more than the noise floor; the right to propose corrections to the vendor table, meaning names the judge wrote that should or should not read as Mimecast Email Security, applied by version and listed in the change log; and a one-line description supplied by the vendor and marked as such.

It does not get any change to labels, shares or verdicts, any preview, or any say over which quotes appear. A verification link goes to your work email; an address at mimecast.com is approved on the spot, any other address is reviewed by hand.

Your name and company appear on the claimed page, or the company alone if you ask below. A title and a LinkedIn address appear there too if you give them, and are left off if you do not. Your email address is never published.

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