MS-102 Deploy and manage a Microsoft 365 tenant Practice Question
Your company has a Microsoft 365 E5 tenant. You need to ensure that all external emails are marked with a warning banner at the top of the email body. What should you configure?
⚠ Common exam trap
Many candidates confuse 'external email tagging' (which adds a header or subject prefix) with adding a visible banner inside the email body, leading them to choose Option B instead of the correct mail flow rule.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
A mail flow rule (transport rule) to add a disclaimer.
A mail flow rule (transport rule) in Exchange Online can be configured to prepend a disclaimer (warning banner) to the body of all external emails. This is the only mechanism that directly modifies the email body content for inbound or outbound messages based on sender/recipient criteria, such as when the sender is external to the organization.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
A Safe Attachments policy in Microsoft Defender for Office 365.
Why it's wrong here
Safe Attachments is a threat protection feature that detonates email attachments in a sandbox and can quarantine or replace malicious files. It does not modify the visible message envelope or introduce a disclaimer banner. Because the requirement is to visually tag external emails with a warning banner, this policy cannot achieve that result.
- ✗
External email tagging in the Microsoft 365 Defender portal.
Why it's wrong here
External email tagging is a built-in toggle in the Defender portal that appends a generic 'External' tag to the subject line and inserts a predefined banner. It is not a configurable policy, as administrators cannot set custom disclaimer text, HTML formatting, or apply it based on conditions. For tailoring a warning banner to your organization's requirements, a transport rule is necessary.
- ✗
A DLP policy with a sensitive information type.
Why it's wrong here
DLP policies with sensitive information types are designed to detect and protect regulated data by using actions such as blocking, quarantining, or alerting. They do not have a mechanism to insert a visual disclaimer or banner into an email's body. Therefore, a DLP policy cannot satisfy a requirement to add an external email warning banner.
- ✓
A mail flow rule (transport rule) to add a disclaimer.
Why this is correct
A mail flow rule (transport rule) in Exchange Online can apply a disclaimer to emails that meet specified conditions, such as being sent from an external sender. This rule can append a customized HTML banner to the message header or footer, which is exactly the visual warning required. This is the correct method for adding a disclaimer to external emails.
Go deeper
Related to this question
Learn chapter
Exchange Mobile Device Policies (OWA)
Key term
Exchange Online
Exchange Online is Microsoft's cloud-based email, calendar, and contact hosting service that is part of the Microsoft 365 suite, allowing organizations to manage corporate messaging without maintaining their own mail servers.
Key term
Microsoft 365
Microsoft 365 is a subscription-based cloud service from Microsoft that combines productivity tools like Office apps with security, device management, and online storage.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This MS-102 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the MS-102 exam.