Mail apps, printers, scanners and ERP keep using plain IMAP, POP3 and SMTP — PostMount delivers it all through Microsoft 365, even with basic authentication turned off.
Free 14-day trial · no credit card · no changes in your tenant
From Microsoft Store, no admin rights on the computer.
Your regular work sign-in; your mailbox appears by itself, shared ones in a click.
Server, ports, user name and password — copy them from PostMount.
IMAP, POP3 and SMTP AUTH stay turned off in Microsoft 365 — PostMount uses modern sign-in on their behalf.
Works when IMAP, POP3 and SMTP AUTH are disabled in Exchange Online: PostMount signs in with OAuth and sends through Microsoft Graph.
Printers, scanners and ERP send on port 25 without a password — only from the IP addresses you allow.
Read and send from shared mailboxes you have Full Access and Send As to — each with its own password.
If Microsoft 365 limits sending or the connection drops, messages wait in a queue on disk and go out automatically.
Save a whole mailbox to PST, EML, MBOX or MSG — for archives, migrations and handovers, without Outlook.
This computer only, the local network, or a list of allowed IPs — with a live check of Windows Firewall rules.
Multifunction printers, scanners and ERP systems rarely support modern sign-in. Point them at PostMount as their SMTP server — the mail goes out through Microsoft 365 from the mailbox you choose:
Criterion |
Through PostMount |
Directly to Exchange Online |
|---|---|---|
|
Apps without OAuth support |
work as before | "authentication failed" |
|
Scan to email |
port 25, no password | SMTP AUTH or a mail connector |
|
Changes in the tenant |
none | re-enable legacy protocols |
|
Passwords on devices |
local only, per mailbox | the Microsoft 365 password |
|
When Microsoft 365 limits sending |
queued and sent later | the device shows an error |
Your Microsoft 365 password never leaves the sign-in window — apps and devices get a separate local password.
PostMount runs on one office PC or server and serves the whole office; the 14-day trial starts by itself after the first sign-in.
See where the license is active and move it to a new computer in one click — after a test run or a hardware replacement.
Sign-in state, services and ports, Windows Firewall rules, active mailboxes and a readable event log — in one window.
Where your organization requires app approval, an administrator grants it once — no other settings in the tenant.
Try everything for 14 days without limits — then pick the plan that matches your office.
Everything without limits — to see how many apps and devices you really have.
All features, no limits
Starts by itself after sign-in
No credit card
For a few mail apps and a couple of printers.
$49.99 per year — like paying for 10 months, not 12
Apps on this computer — unlimited
Up to 3 computers on the network
Up to 3 gateway devices
Unlimited mailboxes
For dozens of printers, ERP and computers across the office.
$199.99 per year — like paying for 10 months, not 12
Unlimited computers on the network
Unlimited gateway devices, subnets
Unlimited mailboxes
Pay from any country: cards and invoices via Paddle
One license covers one computer running PostMount. Prices in US dollars, excluding taxes. Paddle shows the final amount in your currency, including taxes, at checkout. Payments are handled by Paddle — Merchant of Record.
Yes — that is exactly what PostMount is for. It talks to Microsoft 365 through Microsoft Graph with modern sign-in, while your apps and devices keep using plain IMAP, POP3 and SMTP. Nothing needs to be re-enabled in the tenant.
Still have a question? Write to us: support@postmount.app
14 days free · set up in minutes · no changes in your tenant
Download for Windows
