smtp-test-tool is a single static binary that lets IT teams verify
SMTP / IMAP / POP3 connectivity, exercise STARTTLS / SSL / AUTH
paths, and translate cryptic 5.7.x bounce codes into IT-actionable
remediation steps. Ships with a CLI and a native GUI in one
download; runs entirely on rustls (no OpenSSL); stores credentials
in the Windows Credential Manager.
Publisher’s description
What is SMTP Test Tool?
SMTP Test Tool by StruisICT is open-source Windows software in the email clients category. It is written in Rust.
Installation and requirements
The publisher provides Portable installers for 64-bit Windows. It runs without installation (portable).
Popularity and file types
The source code on GitHub (StruisICT/smtp-test-tool) has 4 stars. Similar programs include Proton Mail Bridge, Tuta Mail and Mailspring.
Project description on GitHub: “Cross-platform SMTP/IMAP/POP3 connectivity tester with IT-actionable diagnostics. Single static binary, CLI + GUI, WCAG 2.2 AAA, dark/light auto-follow.”
Pros / Cons
Pros
- Open source: the code can be inspected and built by anyone
- Portable: runs without installation
Cons
- No native ARM64 build
In short: SMTP Test Tool is an open-source email client tool for 64-bit PCs.
Is SMTP Test Tool safe to download?
- The file is served by github.com, the publisher’s own domain
- The download link uses HTTPS
- A SHA256 hash is published, so you can verify the file:
4DAE00B126096811D39A5ECF1569BC3234055587AC0874C5E6E584B0F423FC0C· Open the VirusTotal report for this hash - The link has not been checked yet
- The source code is public
- ExeAtlas does not host, wrap or modify installers
Related guide: How to check a file’s SHA256 hash on Windows
Recent versions
All 1 versions ›| Version | Date | Size | Files |
|---|---|---|---|
| 0.2.1Latest | July 10, 2026 | — | 64-bit ZIP |
Install from the command line
Silent install ›winget install --id StruisICT.SmtpTestTool -eProgram files (.exe): smtp-test-tool.exe, smtp-test-tool-gui.exe
Related guide: How to use winget: install and update apps
Information
- Publisher
- StruisICT
- Category
- Email clients
- Licence
- MIT OR Apache-2.0
- Price
- Free
- Source code
- github.com/StruisICT/smtp-test-tool
- Written in
- Rust
- Requires
- Windows 11 / 10
- Architecture
- 64-bit
- Installer
- Portable
- Version
- 0.2.1
- Released
- July 10, 2026
- Added to the catalogue
- July 28, 2026
- Versions listed
- 1
- GitHub stars
- 4
- Website
- github.com
- winget ID
- StruisICT.SmtpTestTool
Ratings and reviews
No reviews yet. Be the first to rate it.
Alternatives to SMTP Test Tool
See all ›-
Open source26.2K ↓ -
Tuta Mail362.261023.2Tutanota is an email client with a strong focus on security and privacy that lets you encrypt emails on all your devices.Open source50.1K ↓ -
Mailspring1.26.2Boost your productivity and send better email with Mailspring, the best mail client for Mac, Linux, and Windows.Open source7.7K ↓ -
eM Client11.0.1054Fast email client with full Gmail, Hotmail and other services synchronisation. Best replacement for MS Outlook or Thunderbird. Free version for Home users.Free98.1K ↓ -
Open source11K ↓ -
MFCMapi26.0.26291.01Provides access to MAPI stores to facilitate investigation of Exchange and Outlook issues and to provide developers with a sample for MAPI development.Open source5.7K ↓ -
Open source592 ↓ - Mozilla Thunderbird (en-US)158.0.1Thunderbird is a free email application that is easy to set up and customize - and it's loaded with great features!Open source
Frequently asked questions
Is SMTP Test Tool free?
Yes. SMTP Test Tool is open-source software under the MIT OR Apache-2.0 licence.
Is SMTP Test Tool safe to download?
The download comes from github.com, which belongs to the publisher; ExeAtlas does not host or change the file. Compare its SHA256 hash with the one shown here, or open the VirusTotal report for that hash.
How do I install SMTP Test Tool with winget?
Open PowerShell or Windows Terminal and run the winget command shown on this page. winget downloads the official installer and checks its SHA256 hash before running it.
Does SMTP Test Tool run on ARM (Windows on Arm)?
There is no ARM64 build; Windows 11 on Arm can run the 64-bit version through emulation.
Can I use SMTP Test Tool without administrator rights?
Yes, it is portable: unpack and run it.
What are alternatives to SMTP Test Tool?
Proton Mail Bridge, Tuta Mail, Mailspring, eM Client and Claws Mail. The alternatives page compares them.
