Printers and business apps that send with a password: plan for late 2026.
Microsoft 365 will turn password-based SMTP AUTH off by default in late December 2026. An SMTP relay sends email for your printers and business apps.
- Your mailboxes stay on Microsoft 365
- Free, no card and no expiry
- Servers and data in the EU
relay.mailsenpai.com2525from your customer areascanner@yourdomain.exampleLate December 2026 Password-based SMTP login is turned off by default.
The dates to plan for
A summary of Microsoft’s announcement. There is no immediate change.
- 1Until December 2026today
Works as it does now
Password-based SMTP login continues as it does today.
- 2Late December 2026
Off by default
Existing organisations can ask their administrator to turn it back on if needed.
- 3New tenants after December 2026
Unavailable by default
OAuth is the supported sign-in method; many older devices do not support it.
- 4Second half of 2027
Final removal date announced
Microsoft will announce when password-based SMTP login is removed altogether.
What changes for your devices
For existing tenants, password-based SMTP login will be off by default .Check your device
Before switching, check your device
Look for these five options in its network settings. Availability depends on the model and firmware.
1. Find these settings
- Server
editable SMTP server fieldto checkcheckok - Port
you can enter port 2525or 587to checkcheckok - Encryption
STARTTLS (often called TLS)to checkcheckok - Sign-in
username and passwordto checkcheckok - Sender
an address on your own domainto checkcheckok
2. Enter these four details
relay.mailsenpai.comThe same for every app.
2525With STARTTLS: the connection is encrypted.
from your customer areaFind it in your area once the service is activated.
from your customer areaPut it only in the app settings, never in your code.
Older device, or not sure? Use the contact form before activating, so we can check the model with you.
Ask us firstDevice sending, not your mailboxes
Your mailboxes stay on Microsoft 365. Only the email from connected devices and apps goes through the relay.
Stays on Microsoft 365
- Office mailboxes
- Calendars and contacts
- Incoming email
No mailbox migration.
Goes through the relay
Printers and scanners
Scan-to-email uses the relay, with your domain as sender.
Business software
Invoices and reminders use the four details in the SMTP settings.
Websites and forms
Email from your website and contact forms.
Sending log
Each send and its result: 7 days of logs on the free plan, 90 on paid plans. A weekly email report in Italian every Monday.
- Free, no card and no expiry
- Paid plans from €12.90/month + VAT (annual plan)
- Servers and data in the EU
Frequently asked questions
Can I keep sending through Microsoft 365?
Temporarily, an existing organisation’s administrator can turn password-based SMTP login back on. If your device supports OAuth, it can stay on Microsoft 365. A relay is an option for devices without these routes.
Does my printer support port 2525 or 587 with STARTTLS?
It depends on the model and firmware. In its network settings, look under SMTP or scan to email for an editable port and STARTTLS or TLS. If these are unavailable, contact us before activating.
Will the emails still use my domain?
Yes, with a DKIM signature on your domain. We give you the DNS records to add and check them for you. Keep the SPF record you use for Microsoft 365: add only our part.
Does this change my incoming email?
No. SMTP Senpai handles only the outgoing email of the devices and apps you connect. Mailboxes, calendars and incoming email stay where they are.
What does it cost?
The free plan has no expiry and requires no card. For more volume, paid plans start at €12.90 a month for 10,000 emails on the annual plan (VAT excluded). There is no automatic switch to a paid plan.
More useful pages
Move your device sending before the default changes.
- Free, no card and no expiry
- No expiry: stay on the free plan while it meets your needs
- Documentation and tickets in Italian on the free plan
and no expiryStart free