Hi Alex,
Sincere apologies for the delay in response for this. While we do not have a Mimecast connector yet, you may still be able to integrate with it using our HTTP or SDK connector. You can learn more about those here:
The key differences between HTTP and SDK are as follows:
Send us a ticket, we will try our best to assist you with your problem
Alex Shchukin
Mimecast connector
We need Workato connector for Mimecast
https://community.mimecast.com/community/mc-blogs/blog/2018/04/03/build-powerful-integrations-announcing-the-mimecast-api-developer-portal