Photocopier OAuth setup guide — how to prepare for Office 365 SMTP authentication changes (2025–2026)

Microsoft is retiring Basic SMTP Authentication for Office 365, which will change how many multifunction printers and copiers send scanned documents by email. This guide explains what’s happening, why modern authentication (OAuth 2.0) matters for scan-to-email, and how to avoid interruptions from the initial rollout on October 1, 2025 through full enforcement on March 31, 2026. You’ll find which devices are most likely to stop working, practical fixes (upgrade, SMTP relay, Direct Send or managed services), and a straightforward checklist to assess and remediate your fleet. This is written for small and medium business owners, office managers and IT teams who currently use smtp.office365.com and need a clear plan. Read on for timelines, quick device checks, solution comparisons, compatibility pointers and how to book a free compatibility assessment with Copier King to keep scan-to-email running after the change.

What is the Office 365 SMTP authentication change — and why it matters

Microsoft is phasing out Basic SMTP AUTH (username/password) and moving services that submit mail via smtp.office365.com to Modern Authentication such as OAuth 2.0. That matters because many copiers and MFPs were set up to submit email with static credentials; those setups will fail once Basic Auth is removed and scan-to-email will stop on affected devices. Modern Authentication uses short-lived tokens and ties into Azure AD controls, allowing MFA and conditional access to reduce credential exposure and improve security. If any of your devices still use smtp.office365.com with Basic Auth, you should check compatibility now and pick a remediation route before the enforcement dates. Key milestones below summarise the rollout and what to expect.

• October 1, 2025: rollout begins — you may start seeing authentication changes.
• March 31, 2026: Microsoft enforces the deprecation and blocks Basic SMTP Authentication.
• Impact summary: Devices using Basic Auth to smtp.office365.com may stop sending email, interrupting scan-to-email workflows.

Those dates create a clear timetable for action. If your copiers rely on smtp.office365.com, arrange a compatibility assessment with a trusted supplier without delay.

Office 365 SMTP authentication changes — what they mean for multifunction devices Microsoft’s removal of Basic SMTP Authentication will affect how MFPs and copiers deliver scanned documents via email. This note outlines the core impact, why OAuth 2.0 is the preferred replacement, and practical ways to avoid disruption from the October 1, 2025 rollout to the March 31, 2026 enforcement. It highlights at-risk devices, remediation choices (upgrade, relay, Direct Send or managed services) and a step-by-step checklist for assessing and fixing your estate.

What is Basic SMTP Authentication — and why is Microsoft removing it?

Basic SMTP Authentication is a legacy method where devices authenticate to smtp.office365.com with a username and password. Because those credentials are static they can be exposed and cannot be protected by MFA or conditional access, leaving accounts vulnerable to theft and brute-force attacks. Microsoft is deprecating Basic Auth to reduce the attack surface and bring mail submission in line with modern identity controls. That’s why token-based OAuth 2.0 is the safer alternative — and why some older devices can’t simply be made secure with a firmware update and will need different solutions.

How does OAuth 2.0 improve security for photocopiers?

OAuth 2.0 issues short-lived tokens instead of storing long-lived passwords on devices. That reduces the chance of reused credentials, and it supports MFA and conditional access via Azure AD. For MFPs, OAuth lets administrators manage access centrally, revoke tokens without touching each device, and apply risk-based controls. Overall, token-based authentication is easier to manage long term and is the recommended route where manufacturers support it instead of relying on Basic Auth workarounds.

Who will be affected by the multifunction printer Basic Auth deprecation in 2026?

Only organisations whose copiers or MFPs submit mail to smtp.office365.com using Basic SMTP AUTH are in scope — other SMTP providers or different submission methods aren’t affected. Many older devices predate OAuth support and lack the hardware or secure storage needed to implement it, so they can’t be patched by firmware alone. Typical at-risk setups are legacy office copiers in SMBs where scan-to-email was configured once with a service account and left untouched. The first practical step is to identify which devices use smtp.office365.com so you can decide whether to upgrade, relay or use an alternative send method.

Which photocopiers and MFPs are likely to fail scan-to-email?

Risk depends on device age, manufacturer support for OAuth and how scan-to-email was configured (per-user credentials, shared service accounts or IP-authenticated relays). Common brands in the field — Toshiba, Develop, Konica Minolta, Sharp and Utax — have mixed model support: newer business models often offer OAuth firmware, whereas older units usually don’t. Hardware limits such as missing secure token storage, weak TLS support or missing OAuth libraries mean firmware can’t always add modern auth, and those devices will need replacement or an alternate sending arrangement. The next section covers the business risks of leaving unsupported devices as they are and how to prioritise remediation.

What business risks come from not upgrading before October 2025?

Leaving affected devices unchanged risks immediate disruption: reception, HR, accounts and other teams that rely on emailed scans may lose key workflows. Last-minute emergency fixes are often more expensive, lead to rushed equipment choices and can introduce compliance gaps if insecure workarounds are used. Manual alternatives increase staff time and can delay client work or regulatory reporting. Recognising these risks helps you prioritise critical devices, schedule assessments and pick the most cost-effective remediation path.

What are your options to keep copier scan-to-email working with modern authentication?

There are four practical approaches: upgrade to OAuth-capable MFPs, implement an SMTP relay (connector or IP-based), install manufacturer firmware where available, or use Direct Send / High Volume Email for specific cases. Each option balances compatibility, security, cost and deployment time differently — the right choice depends on how many devices you have, whether recipients are mainly internal or external, and your security needs

How can you upgrade to OAuth-compatible photocopiers and MFPs?

Upgrading means choosing OAuth-capable models from supported manufacturers and deciding whether to lease, buy or take refurbished units, then planning deployment and Azure AD integration. A practical upgrade path: take an inventory, prioritise high-use devices, choose models with documented OAuth support and schedule staged replacements to avoid service disruption. Leasing or managed print services spread cost and provide refresh cycles; short-term rentals or refurbished units can cover urgent gaps. Copier King can advise on model selection, provide or lease compatible machines and handle secure configuration so OAuth works correctly out of the box.

How does SMTP relay work as an alternative for legacy devices?

SMTP relay lets devices authenticate by IP address or via an Exchange Online connector rather than with user credentials, enabling legacy copiers to send through smtp.office365.com without Basic Auth credentials. Relay needs network setup, static IPs or an appliance gateway and careful configuration to avoid becoming an open relay. It can be restricted to internal recipients or extended with a properly configured connector. Relay is often a fast, lower-cost fix that preserves security when implemented correctly, though it won’t support conditional access or MFA and is less future-proof than native OAuth. For many SMBs, SMTP relay is a practical compromise while planning a device refresh.

SMTP service extension for authentication — security layer and client verification
When a security layer is negotiated, the SMTP session is reset. During authentication the client verifies the server before proceeding.

Can firmware updates add OAuth to existing devices?

Some newer models already include the hardware and secure storage needed for OAuth and can receive firmware that adds Modern Authentication. But firmware can’t fix genuine hardware limitations such as missing secure token storage or inadequate TLS support; those devices will need replacement. Check manufacturer support pages and release notes for your exact model, and test any firmware-based OAuth update on a single device before rolling it out. When available, firmware is a cost-effective route — Copier King can run firmware checks and staged rollouts as part of a compatibility assessment and remediation plan.

What about Direct Send and High Volume Email as alternatives?

Direct Send and High Volume Email (HVE) are specialist paths where devices send mail directly to recipient servers or use Microsoft HVE channels; they can avoid smtp.office365.com Basic Auth but have limitations. Direct Send commonly restricts deliveries to internal addresses and may not work for external recipients; HVE is designed for bulk sending and usually requires separate provisioning and controls. These options suit specific workflows (internal-only recipients or high-volume use) but aren’t a universal replacement for OAuth-capable submission. Test them carefully before deploying to production.

Bridging legacy systems with IoT — SMTP for machine-to-human notifications
Common protocols include HTTP, SMTP and MQTT. Data from legacy systems is often formatted as JSON for interoperability, then routed via MQTT for machine-to-machine, SMTP for machine-to-human notifications, and HTTP for human-to-machine interactions.

How can you check if your photocopier supports OAuth 2.0?

A compatibility assessment confirms whether devices support OAuth, what firmware is available and which remediation path is most cost-effective. A proper assessment includes an inventory, review of current scan-to-email settings, live tests against smtp.office365.com, review of manufacturer notes and a remediation plan with costs and timelines.

What steps should you take now to avoid scan-to-email disruption in 2026?

1. Immediate: Inventory devices, identify those using smtp.office365.com and flag critical endpoints.
2. Near-term: Book a compatibility assessment and decide on remediation (relay, firmware or upgrade).
3. Implementation: Carry out remediation in priority order, test each device and verify external delivery.
4. Ongoing: Enrol in managed print services to keep devices updated and plan refresh cycles.

This staged plan feeds directly into booking an assessment and setting timelines to meet the October 2025–March 2026 windows so your operations remain uninterrupted and secure.

What is the recommended timeline for upgrading or configuring your devices?

Recommended timing is simple: take an inventory and book an assessment now, complete critical remediations in the months leading up to October 1, 2025, and finish testing and monitoring before the March 31, 2026 enforcement. Prioritise high-use devices and departments that rely on scanned documents, stage upgrades or relay deployments to avoid simultaneous outages, and leave a contingency window for unexpected issues. Follow the assess → implement → test sequence to maximise the chance of uninterrupted scan-to-email service and align remediation with business needs.

Frequently asked questions

What should I do if my photocopier is not compatible with OAuth 2.0?

If your photocopier can’t use OAuth 2.0, you have options. Upgrade to a newer model that supports modern authentication (the most secure long-term fix), or implement an SMTP relay so the existing device can keep sending without Basic Auth. Relay can be a temporary or long-term solution depending on your needs. Speak to a service provider like Copier King to weigh cost, timing and security and pick the best route for your estate.

How can I keep my office’s email scanning secure after the transition?

To keep scanning secure, implement MFA where possible, keep device firmware up to date, and consider managed print services for ongoing support and monitoring. Regular compatibility checks and a proactive update schedule reduce the chance of vulnerabilities. Managing devices centrally via MPS or Azure AD policies also helps enforce consistent security controls across your fleet.

What are the costs of upgrading to OAuth-capable devices?

Costs vary by number of devices, brand and whether you purchase, lease or choose refurbished units. Newer models with built-in OAuth have higher upfront cost but deliver better security and longer life. Leasing spreads the cost and can be easier for SMBs. We recommend a cost-benefit review and supplier quotes to find the right financial approach for your organisation.

How can I test whether my current devices will work with the new authentication method?

Run a compatibility assessment: check the device model against manufacturer specs for OAuth support, test scan-to-email with smtp.office365.com and review available firmware updates. If possible, configure OAuth on a single device in a controlled environment. A thorough provider-led assessment will show which devices can be updated and which need relay or replacement.

What happens if I ignore the Basic Auth deprecation?

Ignoring the change risks operational disruption: devices that rely on Basic SMTP Authentication will stop sending email, causing workflow outages and potential compliance gaps. Emergency fixes are costly and disruptive. Act now to assess devices and plan remediation to avoid downtime and extra expense.

Can I use third-party SMTP services instead of Office 365?

Yes — third-party SMTP providers can be used for scanned documents, but they usually require extra configuration and may not integrate seamlessly with your existing email setup. Ensure any third-party SMTP supports modern authentication like OAuth 2.0 and check reliability and support levels before switching.

What should I do if I have many devices to upgrade?

Start with a full inventory to identify affected devices and prioritise by usage and business impact. Book a compatibility assessment to determine the best remediation per device. Stage upgrades to minimise disruption and consider leasing to spread costs. Working with a service provider helps coordinate replacements, relay setup and testing across the estate.

Conclusion

Moving your multifunction printers to OAuth 2.0 is essential to keep scan-to-email reliable and secure. By understanding the Basic Auth deprecation and choosing the right remediation — upgrade, relay, firmware or managed services — you can avoid disruption. Don’t wait: book a free compatibility assessment with Copier King today so your devices are ready for the upcoming Office 365 authentication changes and your business keeps running smoothly.