Backup all SQL Server databases with PowerShell

backup-all-databases.ps1

# SQL Server parameters
$serverInstance = 'localhost'

# Backup parameters
$backupDirectory = 'C:\path\to\backup\dir'
$retentionDays = 10

# Mail parameters
$mailFrom = '[email protected]'
$mailTo = '[email protected]'
$mailSubject ="[FAIL] SQL Server backup on $env:computername"
$smtpServer = '1.2.3.4'


# No more parameters, don't touch the code below this comment.
# (or you will die in agony)

try {

    # Remove old backups
    $dateLimit = (Get-Date).AddDays(-1 * $retentionDays)
    Get-ChildItem $backupDirectory |
    Where { $_.CreationTime -lt $dateLimit } | 
    Remove-Item

    # Backup all databases
    Get-SqlDatabase -ServerInstance $serverInstance |
    Where { $_.Name -ne 'tempdb' } |
    foreach{
        $backupFile = "$($_.NAME)_db_$(Get-Date -UFormat %Y%m%d%H%M).bak"
        $backupFile = Join-Path $backupDirectory -ChildPath $backupFile

        Backup-SqlDatabase -DatabaseObject $_ -CompressionOption On -BackupFile $backupFile
    }

} catch {
    $message = $_.Exception.GetType().FullName + "`n" +
               $_.Exception.Message
    Write-Host -Foreground Red -Background Black $message

    Send-MailMessage -From $mailFrom `
                    -To $mailTo `
                    -Subject $mailSubject `
                    -Body $message `
                    -SmtpServer $smtpServer
}