Microsoft switches off SMTP basic authentication at the end of December 2026
Your printer keeps sending email, even after December.
Multifunction printers, NAS, business software and websites that send with a username and password stop working with Microsoft 365. smtp365 receives their messages and sends them from your mailbox: same address, no DNS changes, everything in Sent Items.
No credit card. 2 mailboxes and 300 messages to really try it out.
- SMTP server
- mail.smtp365.it
- Port
- 587
- Connection
- STARTTLS
- Authentication
- On
- User
- mfp-second-floor
- Password
- ••••••••••••
- Sender
- scanner@smithandco.com
What is changing in Microsoft 365
Microsoft is removing sending with a username and password (SMTP AUTH) from Exchange Online. People who sign in the modern way won't notice. Devices that only know a username and password will.
-
End of December 2026
Disabled by default on every existing tenant. An administrator can turn it back on, but only temporarily.
-
New tenants
Tenants created after December 2026 never have it: there is nothing to turn back on.
-
Second half of 2027
Microsoft will announce the date of the final removal: from then on it can no longer be turned back on.
What stops sending
- The multifunction printer that scans to email
- The NAS that warns you when a disk fails
- The business software that sends invoices and reminders
- The contact form on your WordPress site
- Gmail sending as your company address
- Alarms, PLCs and cameras that send notifications
Three steps, and the device sends again
No software to install in the office and no changes to Exchange. All you need is a Microsoft 365 sign-in and the details to enter in the device.
-
1
Sign in with Microsoft 365
Sign in with your account and authorise sending from your mailbox. One minute, and it is connected.
-
2
Create one credential per device
Every printer, NAS or program gets its own username and password. If one is compromised, you disable it and the others carry on.
-
3
Enter it in the device
Server mail.smtp365.it, port 587. The message leaves from Microsoft's servers with your address.
Managing many mailboxes? Use organisation mode.
An administrator authorises the tenant once and enables the mailboxes you need, shared ones included, without every colleague having to sign in. You can limit it to a group.
Just like before, only tidier
For recipients, the message arrives from your mailbox as always. For whoever runs the office, you can finally see who sends what.
- It arrives, and stays out of spam
- The message leaves from Microsoft's servers with your domain: SPF, DKIM and DMARC are already in place. You don't need to add DNS records.
- You find it in Sent Items
- Every message shows up in the mailbox, as if you had sent it from Outlook. You can turn this off for credentials that only send notifications.
- One credential for each device
- The password is shown only once. You can disable or delete it whenever you like, and each one can only send with its own address.
- From shared mailboxes too
- A device can send as accounts@ or invoices@: we check the permission with a test message.
- A log of every message
- Date, device, sender, recipients and result. Message content is never stored.
- Limits and alerts
- A sending cap per credential limits the damage of a stolen password. We email you if a mailbox needs reconnecting or you are close to your quota.
- Large attachments
- Up to your Microsoft 365 mailbox limit, which is 35 MB unless you have changed it. Colour scans get through.
- Servers in Europe, fast support
- Data stays in the European Union. If a device won't cooperate, a real person answers quickly.
Works with anything that sends email with a username and password
If the device has fields for server, port, username and password, it will work. For the most common ones we have written a step-by-step guide.
Multifunction printers and scanners
Scan to email, reports, toner alerts.
Business software and ERP
Invoices, reminders, purchase orders. Use the general settings.
Alarms, PLCs and cameras
Notifications from systems and machines. Port 25 too, if needed.
There are alternatives. Each one asks for something in return.
Before choosing, look at what it takes to set them up and what you lose along the way.
| Solution | What it takes | The catch |
|---|---|---|
| Turning SMTP AUTH back on | An administrator re-enabling it on the tenant and the mailboxes. | Only works until the final removal. New tenants don't have it. |
| Exchange connector | A static public IP, port 25 open outbound and an updated SPF record. | No Sent Items, no per-device credentials. Doesn't work from connections without a fixed IP. |
| External sending service | A new provider and changes to the domain's DNS records. | Messages don't show up in Sent Items and leave from third-party servers. |
| Microsoft High Volume Email | A dedicated account set up by the administrator. | Only sends to recipients inside the organisation. |
| smtp365 | A Microsoft 365 sign-in and the details entered in the device. | A monthly subscription. Everything else stays as it was: address, DNS and Sent Items. |
Clear pricing, in euros
VAT excluded. Pay yearly and two months are free.
Studio
For professional firms and small offices
€9 per month + VAT
3 mailboxes and 2,000 messages per month included
Business
For companies with several departments and devices
€29 per month + VAT
15 mailboxes and 15,000 messages per month included
Partner
For those who manage Microsoft 365 on behalf of clients
€49 per month + VAT
30 mailboxes and 45,000 messages per month included
Frequently asked questions
Can't find the answer? Write to support@smtp365.it.
Do I need to change anything in DNS or Exchange?
Do you read or keep my messages?
Do I need a Microsoft 365 administrator?
My device only uses port 25. Will it work?
What happens if I change my Microsoft 365 password?
Sort out your devices before December, calmly.
Connect your mailbox, create a credential and try it with one printer. Once it works, move on to the other devices.