27,883 companies use Mimecast, as of October 2026.
Mimecast: Email security gateway. We've found 27,883 companies using Mimecast, most often in Financial Services (13%) and Insurance (9%), typically with 11–50 employees and 50% based in United States.
Customers27,883companies use it
Most popular withPrivate Equity19× more likely than average
We've found 27,883 companies using Mimecast among the 763,989 we've scanned so far. We only count a company when a direct public record backs it up.
What kind of companies use Mimecast?
Mimecast customers are most often in Financial Services (13%), Insurance (9%) and IT Services (8%). The most common company size is 11–50 employees (36% of customers with a known size).
Which countries use Mimecast the most?
Most Mimecast customers we've found are in United States (50%), United Kingdom (24%) and South Africa (6%).
What are the alternatives to Mimecast?
The most used alternatives in the same category are reCAPTCHA (175,873 companies), Let's Encrypt (52,950 companies), GlobalSign (52,118 companies) and Proofpoint (47,630 companies).
How does runsonwhat know a company uses Mimecast?
We read public traces only. For Mimecast that means the company's email records (SPF, MX, DKIM) and the company's published subprocessor list. Every match keeps the record it came from.
SmartsheetCollaboration4.2×more likely
DocuSignFinance & Legal3.5×more likely
DuoSecurity & Compliance3.3×more likely
KnowBe4Security & Compliance3.2×more likely
ZoomCollaboration2.9×more likely
AdobeCollaboration2.4×more likely
OneTrustSecurity & Compliance2.3×more likely
SalesforceSales & CRM2.3×more likely
ExclaimerWorkspace2.0×more likely
AnthropicAI1.8×more likely
AtlassianDev Tools1.8×more likely
Apple BusinessWorkspace1.6×more likely