In a Mimecast Policy, what is the purpose of Source IP Ranges?

The option that highlights the purpose of Source IP Ranges in a Mimecast Policy accurately reflects its functionality. Source IP Ranges serve as a filter for applying a policy specifically based on the IP addresses of the submitting servers. This means that when an email is received, Mimecast can reference the Source IP Ranges to determine if the policy should be enacted based on where the email originated. This is particularly useful for enforcing different security and compliance measures for emails coming from various geographical locations or specific organizations, ensuring a tailored approach to email management.

The other options do not align with the function of Source IP Ranges. Identifying different user roles pertains to user management and permissions rather than IP filtering. Blocking specific email addresses is related to blacklist and filter policies, and limiting email size deals with size constraints rather than the source of the emails. Each of these functions serves a different aspect of email management, but they do not utilize Source IP Ranges in the same way.