Skip to content

Migrating from a Third-Party Email Protection Service to Microsoft Defender for Office 365

Migrating from Third-Party Email Protection to Microsoft Defender for Office 365

Section titled “Migrating from Third-Party Email Protection to Microsoft Defender for Office 365”

Are you currently using a third-party service, such as Pineapp, to protect your email in Microsoft 365? If so, now might be the perfect time to consider transitioning to Microsoft Defender for Office 365.

Recently, I worked with a client who faced challenges managing their email security with Pineapp. With license renewals approaching, we decided to fully migrate to Microsoft Defender for Office 365. This move simplified their operations, reduced costs, and provided advanced, integrated protection. This guide outlines our journey and how you can follow a similar approach.


The Challenge: Complexity and Cost of Third-Party Systems

Section titled “The Challenge: Complexity and Cost of Third-Party Systems”

Many organizations rely on third-party services for email security. While these services often perform well, they introduce significant challenges:

ChallengeImpactBusiness Consequence
ComplexityManaging two platforms (Microsoft 365 and third-party)Increased operational overhead
CostPaying for both Microsoft 365 and additional serviceEscalating expenses
InconsistenciesDiffering protection methods and user experiencesInefficiencies and security gaps

This was precisely the situation my client faced with Pineapp. Their IT team was struggling to manage multiple systems, while costs for the third-party service were becoming unsustainable.

As license renewal time approached, we were already in the middle of onboarding Microsoft Defender for Endpoint. Recognizing the efficiency of Microsoft’s tools, we decided to expand this integration by adopting Defender for Office 365 for email protection.


The Solution: Microsoft Defender for Office 365

Section titled “The Solution: Microsoft Defender for Office 365”

Microsoft Defender for Office 365 offers a consolidated, cost-effective, and highly secure alternative to third-party systems. By transitioning, organizations can:

BenefitCapabilityBusiness Value
Simplified ManagementCentralize email security within Microsoft 365Reduced administrative complexity
Cost ReductionEliminate third-party service feesLower total cost of ownership
Enhanced SecurityMicrosoft’s advanced threat protectionIntegrated ecosystem protection

This solution addressed all the issues my client faced, and we immediately began planning the migration.


Migrating to Defender for Office 365 requires careful planning. We followed Microsoft’s recommended three-phase approach:

The preparation phase focuses on laying the groundwork for a smooth transition.

We documented Pineapp’s existing settings, such as rules, exceptions, and customizations. This was critical because access to these settings would no longer be possible after terminating the service.

We reviewed the client’s existing Microsoft 365 settings to identify unnecessary configurations and simplify their email environment.

The client had two external services that sent emails on behalf of their domain. We verified these services’ SPF, DKIM, and DMARC configurations to ensure compatibility with Defender for Office 365.

Fortunately, Pineapp’s mail routing rules were minimal, so we didn’t need to make significant adjustments.

We worked with the client to decide how spam and bulk mail should be handled. For this project, we opted to quarantine spam and send bulk emails to the Junk Email folder.


With the groundwork in place, we moved on to configuring Defender for Office 365.

Before we started using ORCA, we first created pilot groups for testing features like Safe Attachments, Safe Links, and anti-spam policies. These groups were designed to test the impact of the migration on a smaller subset of users before rolling out changes across the entire organization.

We maintained the SCL=-1 rule within the Exchange transport rules. This rule ensured that messages routed through Pineapp bypassed Microsoft’s spam filters, avoiding potential conflicts and ensuring smooth email flow during the transition.

After setting up the pilot groups and maintaining the SCL=-1 rule, we used the Office 365 Recommended Configuration Analyzer (ORCA) PowerShell module to scan Defender policies and identify any gaps. ORCA provided actionable recommendations, ensuring we followed Microsoft’s best practices.

FeatureConfigurationBusiness Impact
Safe AttachmentsEnabled dynamic delivery for quick email delivery while scanning attachmentsFaster email delivery with security
Safe LinksEnabled time-of-click URL verification extending to Teams and Office documentsComprehensive protection across platforms
Anti-Spam PoliciesMigrated block/allow lists from Pineapp, enabled BCL filtersReduced false positives, better spam control

We configured user reporting tools to empower employees to report suspicious emails, enhancing the organization’s security posture.


The final phase involved onboarding all users and completing the migration to Defender for Office 365.

We began by training the client’s security team on Defender for Office 365 tools, such as Threat Explorer and Attack Simulator. This training enabled them to proactively manage and respond to security threats more effectively.

Refine Spoof and Impersonation Protections

Section titled “Refine Spoof and Impersonation Protections”

Based on user feedback and recommendations from ORCA, we refined the settings for spoof intelligence and impersonation protection. This fine-tuning allowed us to balance security with user experience.

We gradually expanded the pilot group throughout the organization, making adjustments along the way based on user reports. This ensured that we addressed any issues promptly and refined the policies for better effectiveness.

StepActionResult
Disable SCL=-1 RuleDisabled the mail flow rule that bypassed spam filteringAll email filtering now handled by Defender
Update MX RecordsUpdated MX records to point directly to Microsoft 365Completed transition to Microsoft filtering

As part of the final migration steps, we also configured external service connectors to ensure proper email flow for external services that send emails on behalf of the client’s domain.


While the migration was successful, it wasn’t without challenges:

ChallengeSolutionKey Learning
Printer ConfigurationReconfigured printers to use Direct Send with Microsoft 365 connectorLegacy devices require special consideration
Customization DifferencesCreated creative solutions for Pineapp settings that didn’t translate directlyNot all features have 1:1 equivalents
User TrainingProvided guidance on handling quarantined emails and reporting toolsUser education is critical for adoption
False PositivesFine-tuned policies based on user feedbackInitial tuning period is expected

Migrating from a third-party email protection service like Pineapp to Microsoft Defender for Office 365 offers numerous benefits, including simplified management, reduced costs, and enhanced security. By following the three-phase approach outlined above and leveraging tools like ORCA, you can ensure a smooth transition for your organization.

For my client, this migration not only addressed their immediate challenges but also laid the foundation for a more secure and efficient email environment. Whether you’re facing similar issues or simply looking to streamline your operations, Defender for Office 365 is a powerful solution worth considering.

Key Takeaway: The migration to Microsoft Defender for Office 365 provides significant operational and security benefits when properly planned and executed using a phased approach.

Ready to migrate or have questions about the process? Let’s discuss how Microsoft Defender for Office 365 can work for your organization.