Answer:
The four reasons when an inter-office memorandum would be more appropriate than sending an email are:
1. To communicate sensitive or confidential information that requires a more formal and secure method of delivery.
2. To document important decisions, policies, or procedures that need to be formally recorded and distributed within the organization.
3. To communicate information to a large group of employees or departments that may not all have access to email or where email could get overlooked.
4. To establish a clear paper trail and documentation of internal communication, especially for important matters that may require reference in the future.