E-mail recent Windows Backup Event Log events to monitor backup status

WindowsBackupEMailEvents.ps1

<#
E-mail recent Windows Backup Event Log events to monitor backup status

This script is intended to run via an OS scheduled task using Windows Task Scheduler.
The script runs under the local computer account e.g. "myuser".
This account needs to have local admin rights to access the Windows Event Log.

To run the script manually:
  %SystemRoot%\system32\WindowsPowerShell\v1.0\powershell.exe -NonInteractive -ExecutionPolicy bypass -File "C:\Scripts\WindowsBackupEMailEvents.ps1"

To set up the sending mail credential, perform the following one-time setup **while logged in as the user that will be running the script**.
The encryption uses a user-specific secret managed by Windows.

  runas /user:myuser powershell.exe
  $SendAccountUserPassword = ConvertTo-SecureString 'SecretPasswordForSendingAccount' -AsPlainText -Force
  $SendAccountUserPassword | ConvertFrom-SecureString | Set-Content "C:\Scripts\sendaccountuser_encrypted_password.txt"

Changelog
2022-04-21 Tim Miller Dyck initial release
2022-05-15 Tim Miller Dyck increase width of event message text from 100 characters to 200 characters
2022-05-29 Tim Miller Dyck fetch only the most recent Windows Backup success message to handle the case where there was more than one successfull backup in the measurement period
#>

# initialize variables
$EventLogName = "Application"
$EventSourceName = "Windows Backup"
$StartTime = (Get-Date).AddDays(-7) # check event data for the previous 7 days
$EventSuccessId = 4098              # this is the "Backup completed successfully" message
$StatusEventMessage = "WARNING: No recent successful backup event found"
$FromEMail = noreply@mydomain.org
$ToEMail = myemail@mydomain.org

# load the sending e-mail address credential
$EncryptedPassword = Get-Content "C:\Scripts\sendaccountuser_encrypted_password.txt" | ConvertTo-SecureString
$FromCredential = New-Object System.Management.Automation.PsCredential($FromEMail, $EncryptedPassword)

# get all recent Windows Backup events
$AllBackupEvents = Get-WinEvent -ErrorAction SilentlyContinue -FilterHashtable @{
                       Logname=$EventLogName
                       ProviderName=$EventSourceName
                       StartTime=$StartTime
                   }
# get the most recent single Windows Backup success event within the search time period (by default, events are returned in newest-first order)
$SuccessBackupEvents = Get-WinEvent -MaxEvents 1 -ErrorAction SilentlyContinue -FilterHashtable @{
                           Logname=$EventLogName
                           ProviderName=$EventSourceName
                           StartTime=$StartTime
                           Id=$EventSuccessId 
                       }

# check if a success event was found
if ($SuccessBackupEvents -ne $null -and $SuccessBackupEvents.Message.Contains("success")) {
    $StatusEventMessage = $SuccessBackupEvents.Message
}

# assemble the e-mail message contents and sending configuration
$MailParams = @{
    SmtpServer = 'smtp.office365.com'
    Port = '587'
    UseSSL = $true
    Credential = $FromCredential
    From = $FromEMail
    To = $ToEMail
    Subject = "Windows Backup status: $StatusEventMessage"
    Body = "<h2>Windows Backup status report</h2>
            <p><b>$StatusEventMessage</b></p>
            <p>Here are all Windows Backup status events since $($StartTime.ToLongDateString()).</p>
            <p><pre>$($AllBackupEvents | Format-Table -Autosize | Out-String -Width 200)</pre></p>"
}

# send the e-mail
Send-MailMessage -BodyAsHtml @MailParams