SMTPly SMTPly
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Try it now. 14 days, every feature.

All Enterprise features, no mail limit and no sign-up. After that, a license is required for continued use. Your configuration and logs are kept.

SMTPly for Windows

x64 installer · includes .NET 10 · approx. 97 MB

Download SMTPly-Setup-latest.exe

Version 1.9.0 · SHA-256: c05a79206e21798f3f87d8f480776addd4f6c9fee25973fbf3feef147234ac58

What's new in this version? · All release notes

System requirements

  • Windows Server 2016, 2019, 2022, 2025 or Windows 10/11 (x64)
  • Administrator rights for the installation
  • A Microsoft 365 tenant with an admin account for consent
  • Port 25 or 587 free on the chosen address
Digitally signed as IT-Beratung - Andreas Hähnel, via Azure Artifact Signing.
Setup

Ready in four steps.

Most installations are done in under ten minutes, test mail included.

  1. Run the installerRun as administrator. SMTPly goes to Program Files\SMTPly and runs as a Windows service.
  2. Connect Microsoft 365Sign in once with an admin account and consent. SMTPly creates the app registration itself. Prefer doing it by hand? Guide
  3. Repoint your devicesIn the printer, ERP or application, set the SMTP server to your Windows server. No sign-in needed.
  4. Send a test mailIt shows up in the mail tracker within seconds. If not, the system log tells you why in plain words.
SMTPly Setup

Setup complete

SMTPly has been installed on this computer.

  • Program files copied
  • Windows service “Smtply” created
  • Service started
Finish
Wizard starting. Next, you connect Microsoft 365.

If Windows warns you

Signed

For a freshly published version, SmartScreen often still reports an "unrecognized app". Microsoft judges how often this exact file has been downloaded. The signature itself is verified and has been used consistently since version 1.7.18.

  • In the browser: "Keep", then "Keep anyway"
  • On launch: "More info", then "Run anyway"
  • Check the signature: right-click, Properties, Digital Signatures
  • Compare the checksum: Get-FileHash SMTPly-Setup-latest.exe

Activate your license

One-time

After purchase your license key arrives by email. Paste it under "License" in the app and activate, even in the middle of the trial. The license then belongs to this server.

Moving servers? Release the license in the app and activate the same key on the new server.

Your license key and invoices are always available in the customer portal at Polar. You sign in with a code sent to the email address you bought with.

Compare editions and pricing →

Windows service

Smtply.Service.exe with SMTP listener and relay through Microsoft Graph.

Management app

Smtply.exe with dashboard, system log, settings and setup assistant.

.NET 10 included

No separate runtime, nothing else to install.

All libraries

MSAL, Graph SDK, SmtpServer, Serilog, SQLite. Details in the license notices.

Tested and convinced?

Starter €149, Business €249, Enterprise €499. One-time purchase, one license per server, unlimited mail volume. From 1 November 2026: Starter €199, Business €349.

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