Multi NET-SEND: A Complete Guide to Batch Messaging on Windows### Introduction
Batch messaging across a local network can save time, ensure fast notifications, and help administrators coordinate tasks. Multi NET-SEND is a tool (and a common pattern) for sending NET SEND-style messages to multiple Windows machines at once — useful in environments where classic messenger services are unavailable or where simple pop-up notifications are sufficient.
This guide covers what Multi NET-SEND is, how it works, installation options, practical examples (including batch scripts and PowerShell equivalents), troubleshooting, security considerations, and best practices.
What is NET SEND and why “Multi”?
NET SEND was a command included in older Windows versions (Windows NT/2000/XP) that allowed sending a popup message to another user’s session or computer via the Messenger service. Modern Windows versions removed the Messenger service due to misuse and security concerns, but similar functionality can be reproduced using:
- third-party tools named “net send” clones,
- built-in utilities like msg.exe,
- PowerShell scripts leveraging WMI/WinRM/PSRemoting,
- custom small server/agent programs.
“Multi NET-SEND” refers to sending such messages to multiple targets simultaneously — typically via a script or tool that iterates over a list of hostnames/IPs or reads Active Directory.
When to use Multi NET-SEND
Use Multi NET-SEND for:
- urgent administrative alerts (planned maintenance, reboots),
- classroom or lab notifications,
- short notices to logged-on users in a corporate LAN,
- simple automation-triggered alerts in environments without enterprise messaging systems.
Avoid it for sensitive data, long messages, or environments where users expect modern messaging tools (Teams, Slack, email).
Methods to implement Multi NET-SEND
1) Using msg.exe (built-in for modern Windows)
msg.exe sends messages to a user, session, or remote machine. It’s the simplest modern replacement for NET SEND.
Basic usage:
msg /server:TARGET_COMPUTER * "Your message here" Batch example to send to multiple computers:
@echo off for /f "usebackq tokens=*" %%A in ("computers.txt") do ( msg /server:%%A * "Planned maintenance in 10 minutes. Save your work." ) Notes:
- Requires the Messenger service replacement (Terminal Services / Remote Desktop Services) to accept messages.
- Needs administrative privileges and that the target allows messaging.
2) PowerShell with Invoke-Command and a popup
Use PowerShell to run a remote command that displays a message box:
$computers = Get-Content -Path "computers.txt" $message = "Planned maintenance in 10 minutes. Save your work." $script = { param($msg) Add-Type -AssemblyName PresentationFramework [System.Windows.MessageBox]::Show($msg, "Admin Notice", 'OK', 'Information') } Invoke-Command -ComputerName $computers -ScriptBlock $script -ArgumentList $message -Credential (Get-Credential) Notes:
- Requires WinRM/PSRemoting enabled and appropriate firewall rules.
- Displays a GUI message on the interactive desktop only if invoked in an interactive session context.
3) Using PSExec to run msg or a popup remotely
PsExec (from Sysinternals) can run commands on remote machines and can be used to invoke msg.exe or a PowerShell popup:
psexec @computers.txt -h -u DOMAINdmin -p password msg * "Maintenance in 5 minutes." Notes:
- Passing passwords on command line is insecure; prefer credential prompts or secure methods.
4) Third-party Multi NET-SEND tools
There are dedicated tools that mimic NET SEND and add features like scheduling, logging, and group targeting. When selecting one:
- prefer open-source or well-reviewed utilities,
- check compatibility with your Windows version,
- confirm that no unwanted services are installed.
Example: Robust PowerShell script for batch messaging
A more complete PowerShell script that tries msg first, then falls back to a remote popup via CreateProcess on the user session:
param( [string]$Message = "Attention: maintenance starts in 10 minutes.", [string]$ComputerList = ".mputers.txt", [int]$TimeoutSeconds = 30 ) $computers = Get-Content -Path $ComputerList foreach ($c in $computers) { try { Write-Host "Sending msg to $c..." Invoke-Command -ComputerName $c -ScriptBlock { param($msg) msg * $msg } -ArgumentList $Message -ErrorAction Stop -Credential (Get-Credential) } catch { Write-Warning "msg failed for $c — attempting GUI popup..." try { Invoke-Command -ComputerName $c -ScriptBlock { param($m) Add-Type -AssemblyName PresentationFramework [System.Windows.MessageBox]::Show($m, "Admin Notice", 'OK', 'Information') } -ArgumentList $Message -ErrorAction Stop -Credential (Get-Credential) } catch { Write-Error "Both methods failed for $c: $_" } } } Adjust credentials and remoting settings as needed.
Troubleshooting common issues
- “msg /server:… Access is denied”: ensure you have admin rights and target allows messages.
- No popup appears: target user may not have an interactive session or remoting may display on a different session; GUI popups often fail from service contexts.
- Firewall blocks WinRM/Remote registry: open ports for WinRM (⁄5986) or enable necessary exceptions.
- Password/credential errors with PsExec: avoid plaintext passwords; use secure credential prompts.
Security considerations
- Avoid sending sensitive information via popups. Treat them as insecure channels.
- Use authenticated, encrypted channels (WinRM over HTTPS) for remote execution.
- Minimize credentials exposure; use least-privilege accounts.
- Audit and log sends to avoid misuse and spam-like behavior.
Best practices
- Keep messages short and actionable.
- Maintain an up-to-date target list (computers, groups).
- Use scheduling and throttling for large networks to avoid spikes.
- Test scripts on a small subset before wide deployment.
- Prefer modern enterprise notification systems where available.
Alternatives to Multi NET-SEND
- Microsoft Teams/Slack with bots or webhook integrations.
- Email with high-priority flags.
- Enterprise alerting systems (PagerDuty, Opsgenie).
- Endpoint management tools (SCCM/Intune) with notification features.
Conclusion
Multi NET-SEND-style messaging remains useful for quick, local notifications in controlled environments. Modern implementations rely on msg.exe, PowerShell remoting, PsExec, or third-party tools. Prioritize secure configuration, clear messaging, and testing before broad use.
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