Monitoring scripts with email alerts in PowerShell

Introduction

Monitoring scripts help check if systems or services are working well. Email alerts tell you quickly if something goes wrong.

You want to know if a server is down without checking it all the time.

You need to get notified when disk space is low on a computer.

You want to monitor if a website is reachable and get alerts if it is not.

You want to track if a scheduled task failed and get an email about it.

Syntax

PowerShell

Send-MailMessage -From <sender_email> -To <recipient_email> -Subject <subject_text> -Body <body_text> -SmtpServer <smtp_server>

Replace placeholders like <sender_email> with actual email addresses.

You may need to add credentials or use SSL depending on your SMTP server.

Examples

Sends a simple alert email about a server being down.

PowerShell

Send-MailMessage -From "[e-mail]" -To "[e-mail]" -Subject "Server Down" -Body "The server is not responding." -SmtpServer "smtp.company.com"

Checks disk space and sends an email if free space is below 10GB.

PowerShell

$diskSpace = Get-PSDrive C
if ($diskSpace.Free -lt 10GB) {
  Send-MailMessage -From "[e-mail]" -To "[e-mail]" -Subject "Low Disk Space" -Body "Drive C has less than 10GB free." -SmtpServer "smtp.company.com"
}

Sample Program

This script checks if the Windows Update service is running. If not, it sends an email alert. Otherwise, it prints a normal status message.

PowerShell

$serviceName = "wuauserv"
$service = Get-Service -Name $serviceName
if ($service.Status -ne "Running") {
  Send-MailMessage -From "[e-mail]" -To "[e-mail]" -Subject "Service Alert" -Body "Service $serviceName is not running." -SmtpServer "smtp.company.com"
} else {
  Write-Output "Service $serviceName is running normally."
}

Important Notes

Make sure your SMTP server allows sending emails from your script.

Test your email settings separately before adding them to monitoring scripts.

Use secure methods for credentials if your SMTP server requires authentication.

Summary

Monitoring scripts check system status automatically.

Email alerts notify you quickly when issues happen.

PowerShell's Send-MailMessage cmdlet sends emails easily from scripts.

Practice

1. What is the main purpose of using email alerts in PowerShell monitoring scripts?

easy

A. To notify administrators immediately when a problem occurs

B. To slow down the script execution

C. To store logs locally on the computer

D. To increase the script's runtime

Solution

1. Step 1: Understand monitoring scripts

   Monitoring scripts check system health or status automatically without manual checks.

2. Step 2: Role of email alerts

   Email alerts send notifications immediately when an issue is detected, so admins can act fast.

3. Final Answer:

   To notify administrators immediately when a problem occurs -> Option A

4. Quick Check:

   Alerts = Notify admins fast [OK]

Hint: Email alerts = instant problem notification [OK]

Common Mistakes:

• Thinking email alerts slow scripts
• Confusing alerts with local log storage
• Assuming alerts increase runtime

2. Which of the following is the correct syntax to send an email alert using PowerShell's Send-MailMessage cmdlet?

easy

A. Send-MailMessage -Sender '[e-mail]' -Receiver '[e-mail]' -Title 'Alert' -Content 'Issue detected' -Server 'smtp.example.com'

B. Send-Mail -From '[e-mail]' -To '[e-mail]' -Subject 'Alert' -Body 'Issue detected' -Server 'smtp.example.com'

C. Send-MailMessage -From '[e-mail]' -To '[e-mail]' -Subject 'Alert' -Body 'Issue detected' -SmtpServer 'smtp.example.com'

D. Send-Email -From '[e-mail]' -To '[e-mail]' -Subject 'Alert' -Body 'Issue detected' -SmtpServer 'smtp.example.com'

Solution

1. Step 1: Identify correct cmdlet and parameters

   The correct cmdlet is Send-MailMessage with parameters -From, -To, -Subject, -Body, and -SmtpServer.

2. Step 2: Check each option's syntax

   Send-MailMessage -From '[e-mail]' -To '[e-mail]' -Subject 'Alert' -Body 'Issue detected' -SmtpServer 'smtp.example.com' uses correct cmdlet and parameter names. Others use incorrect cmdlet names or parameter names.

3. Final Answer:

   Send-MailMessage -From '[e-mail]' -To '[e-mail]' -Subject 'Alert' -Body 'Issue detected' -SmtpServer 'smtp.example.com' -> Option C

4. Quick Check:

   Send-MailMessage + correct params = A [OK]

Hint: Send-MailMessage with -From, -To, -Subject, -Body, -SmtpServer [OK]

Common Mistakes:

• Using wrong cmdlet names like Send-Mail or Send-Email
• Incorrect parameter names like -Sender or -Receiver
• Missing -SmtpServer parameter

3. What will be the output of this PowerShell snippet?

if ((Get-Process -Name 'notepad' -ErrorAction SilentlyContinue) -eq $null) {
  Send-MailMessage -From '[e-mail]' -To '[e-mail]' -Subject 'Notepad not running' -Body 'Please start Notepad.' -SmtpServer 'smtp.example.com'
  'Alert sent'
} else {
  'Notepad is running'
}

medium

A. No output because Send-MailMessage blocks output

B. 'Alert sent' if Notepad is not running, else 'Notepad is running'

C. Syntax error due to missing parentheses

D. Always 'Alert sent' regardless of Notepad status

Solution

1. Step 1: Understand the condition

   The script checks if Notepad process exists; if not found, condition is true.

2. Step 2: Analyze the if-else branches

   If Notepad is not running, it sends an email and outputs 'Alert sent'. Otherwise, outputs 'Notepad is running'.

3. Final Answer:

   'Alert sent' if Notepad is not running, else 'Notepad is running' -> Option B

4. Quick Check:

   Process check controls output [OK]

Hint: Check process null means send alert, else normal message [OK]

Common Mistakes:

• Assuming Send-MailMessage blocks output
• Thinking condition always true
• Confusing error handling with syntax error

4. You wrote this script to send an email alert if disk space is low:

$freeSpace = (Get-PSDrive C).Free
if ($freeSpace -lt "100MB") {
  Send-MailMessage -From '[e-mail]' -To '[e-mail]' -Subject 'Low Disk Space' -Body 'Disk space below 100MB' -SmtpServer 'smtp.example.com'
}

But no email is sent even when disk space is low. What is the likely problem?

medium

A. The if condition should use -gt instead of -lt

B. Get-PSDrive does not return Free space

C. Send-MailMessage requires -Port parameter

D. 100MB is not a valid size unit in PowerShell comparison

Solution

1. Step 1: Check the size comparison

   PowerShell does not recognize '100MB' as a valid number; it must be converted to bytes.

2. Step 2: Understand Get-PSDrive output

   Get-PSDrive returns Free space in bytes as a number, so comparing to '100MB' string fails silently.

3. Final Answer:

   100MB is not a valid size unit in PowerShell comparison -> Option D

4. Quick Check:

   Size units must be numeric bytes [OK]

Hint: Use numeric bytes, not '100MB' string in comparisons [OK]

Common Mistakes:

• Assuming Get-PSDrive Free is not available
• Thinking Send-MailMessage needs -Port always
• Confusing less than and greater than operators

5. You want to create a PowerShell monitoring script that checks CPU usage every 5 minutes and sends an email alert if usage exceeds 80%. Which approach correctly implements this?

hard

A. Use a loop with Start-Sleep 300, check CPU with Get-Counter, send email if over 80%

B. Run Get-Counter once, then send email immediately without looping

C. Use a scheduled task to run the script every hour, check CPU, send email if over 80%

D. Use a loop with Start-Sleep 60, check CPU once, then exit

Solution

1. Step 1: Understand monitoring frequency

   Checking CPU every 5 minutes requires a loop with a 300-second (5-minute) sleep between checks.

2. Step 2: Use Get-Counter and conditional email

   Get-Counter can measure CPU usage; if usage > 80%, Send-MailMessage sends alert.

3. Step 3: Evaluate options

   Use a loop with Start-Sleep 300, check CPU with Get-Counter, send email if over 80% uses loop with Start-Sleep 300 and conditional email, matching requirements. Others either run once or wrong intervals.

4. Final Answer:

   Use a loop with Start-Sleep 300, check CPU with Get-Counter, send email if over 80% -> Option A

5. Quick Check:

   Loop + 5 min sleep + CPU check + email = C [OK]

Hint: Loop with 300s sleep and conditional email alert [OK]

Common Mistakes:

• Running check only once without loop
• Using wrong sleep duration
• Confusing scheduled task frequency with script loop