Mimecast vs Perimeter 81: Email Security Comparison (2026)
An independent side-by-side comparison of Mimecast and Perimeter 81 for email security buyers — pricing, features, integrations, and how often each is cited by major AI engines.
AI Citation Scorecard
How often each is cited by major AI engines when buyers ask email security questions. Last 90 days across ChatGPT, Perplexity, Gemini, Claude, and Copilot.
Too early to call — probes still building data.
ChatGPT
Mimecast
6 / 6 probes
100%
ExcellentPerimeter 81
Tracking…
No data yet
Perplexity
Mimecast
6 / 7 probes
86%
ExcellentPerimeter 81
Tracking…
No data yet
Gemini
Mimecast
0 / 6 probes
0%
InvisiblePerimeter 81
Tracking…
No data yet
Claude
Mimecast
6 / 6 probes
100%
ExcellentPerimeter 81
Tracking…
No data yet
Copilot
Mimecast
1 / 6 probes
17%
AveragePerimeter 81
Tracking…
No data yet
Scale:NoneLowFairStrongExcellent
Probes run hourly; each (engine × query) combo retests every ~3 days.
Pricing
Key Features
Mimecast
Feature data is being indexed.
Perimeter 81
Feature data is being indexed.
When to choose Mimecast
Choose Mimecast if your team prioritizes its strengths over Perimeter 81's. Full guidance populates as Mimecast's feature data is indexed.
When to choose Perimeter 81
Choose Perimeter 81 if your team prioritizes its strengths over Mimecast's. Full guidance populates as Perimeter 81's feature data is indexed.