Does Mimecast scan for potentially malicious content in files that download through links by default?

Mimecast does indeed scan for potentially malicious content in files that are downloaded through links by default. This scanning capability is a critical feature of Mimecast's email security, which aims to protect users from threats that may not only be attached to emails but also accessible via links.

By scanning the content of files accessed through links, Mimecast ensures that users are safeguarded against various types of attacks, including malware that may be hosted on external sites or document files that have been compromised. This proactive approach helps to maintain a higher level of security in email communications.

Other options do not accurately represent the default behavior of Mimecast regarding link scanning. While attachments are also scanned, this specific question pertains to links. The scanning of links isn't conditional but instead is part of the comprehensive security measures that Mimecast offers by default. Therefore, stating that it only scans attachments or that it depends on settings would not reflect the standard functionality of the service.