PowerShell删除Exchange空公用文件夹脚本报错时，如何移除报错文件夹以终止无限循环？

我之前也遇到过一模一样的问题：用PowerShell批量删除Exchange空公用文件夹时，只要有某个文件夹删除报错，它就会在每次循环里重新被检测到，导致脚本无限循环跑下去。核心问题就是没把报错的文件夹从后续的检测列表里排除掉，多亏了@Michał Turczyn的提示，我先找到了基础解决方法，后来又逐步优化了性能、日志和通知功能，下面分享完整的思路和最终脚本：

最初的问题脚本 #

先看看我最开始写的有问题的版本，每次循环都会重新拉取所有符合条件的文件夹，但完全没处理报错的文件夹：

# Loop until all empty folders are deleted
do {
    # Get all Public Folders without Mail and Subfolders
    $folders = Get-PublicFolder -Recurse -resultsize unlimited | where{$_.MailEnabled -eq $false -and $_.hassubfolders -eq $false}
    # Filter Folders without Items
    $emptyFolders = $folders | Where-Object -FilterScript {@($_ | Get-PublicFolderStatistics).ItemCount -eq 0}
    # Delete Folders
    $emptyFolders | select folderpath | ForEach-Object {$_.folderpath -join "\\"} | ForEach-Object {"\\" + $_} | Remove-PublicFolder -confirm:$false
} until ($emptyFolders -eq $null)

这个脚本的致命问题：如果某个文件夹删除失败（比如权限不足、被其他进程占用），它会在每次循环的$folders里重新出现，导致无限循环无法终止。

核心解决思路 #

要打破无限循环，关键要做两件事：

1. 维护一个报错文件夹列表，每次删除失败就把该文件夹的唯一标识（EntryID）存入列表
2. 后续循环检测空文件夹时，直接排除这个列表里的文件夹
3. 同时优化Exchange查询逻辑，减少重复拉取数据，降低对服务器的负载

最终优化后的脚本 #

经过两次迭代，我最终的脚本支持多基文件夹检测、错误跟踪、日志记录、邮件通知等功能，完全解决了无限循环问题，还提升了性能：

## Delete empty public folders ##
# Load Exchange cmdlet
Add-PSSnapin Microsoft.Exchange.Management.PowerShell.SnapIn;

# Start logging
$loglocation = "C:\WINDOWS\TEMP\pf_delete_" + (Get-Date).ToString("yyyy-MM-dd") + ".log"
Start-Transcript -Path $loglocation

#Set base public folders
$pfpaths = @(
    "\path\to\folder\one"
    "\path\to\folder\two"
    "\path\to\folder\three"
)

# Run for each base public folder in $pfpaths
foreach ($pfpath in $pfpaths) {
    Write-Host "**********************"
    Write-Host "Process folders in path: $pfpath\."

    # Track folders with error
    $errorFolders = @()

    # Get public folders (only query once per base folder for better performance)
    $folders = Get-PublicFolder $pfpath -Recurse -ResultSize Unlimited

    # Loop until all empty folders are deleted
    do {
        # Track parent folders to re-check after deletion
        $parentFolders = @()

        # Filter folders: exclude mail-enabled, with subfolders, errored, and base folders
        $filterFolders = $folders | Where-Object {
            $_.MailEnabled -eq $false `
            -and $_.HasSubFolders -eq $false `
            -and ($errorFolders -notcontains $_.EntryID) `
            -and ($pfpaths -notcontains $_.Identity)
        }

        # Filter folders with zero items
        $emptyFolders = $filterFolders | Where-Object -FilterScript {@($_ | Get-PublicFolderStatistics).ItemCount -eq 0}

        # Attempt to delete each empty folder
        foreach ($emptyFolder in $emptyFolders) {
            try {
                Remove-PublicFolder -Identity $emptyFolder.EntryID -Confirm:$false -ErrorAction Stop
                Write-Host "- Deleted folder: $($emptyFolder.ParentPath)\$($emptyFolder.Name)\."
                $parentFolders += $($emptyFolder.ParentPath)
            }
            catch {
                Write-Warning "Folder with error: $($emptyFolder.ParentPath)\$($emptyFolder.Name)\."
                $errorFolders += $emptyFolder.EntryID
            }
        }

        # Re-query parent folders to check if they became empty after deletion
        $folders = @()
        $parentFolders = $parentFolders | Select-Object -Unique
        $parentFolders = $parentFolders | Where-Object { ($pfpaths -notcontains $_) }
        foreach ($parentFolder in $parentFolders) {
            $folders += Get-PublicFolder $parentFolder -Recurse -ResultSize Unlimited
        }
        $folders = $folders | Select-Object -Unique
    } until (-not $emptyFolders)
}

# Stop logging and clean up log header
Stop-Transcript
$output = (Get-Content $loglocation -Raw) -replace '(.+\n)+(.+)?(?=output file is)'
$output | Out-File $loglocation

## Send log via email ##
$emailbody = "The following empty public folders were automatically deleted today:`n`n"
$emailbody += $(Get-Content $loglocation -Raw)

# Configure email settings
$fromaddress = "public-folder@domain.com"
$toaddresses = "it@domain.com"
$Subject = "Deleted public folders - $(Get-Date -Format dd-MM-yyyy)"
$smtpserver = "mailserver.domain.com"

# Build and send email
$message = New-Object System.Net.Mail.MailMessage
$message.From = $fromaddress
foreach ($toaddress in $toaddresses) {
    $message.To.Add($toaddress)
}
$message.IsBodyHtml = $false
$message.Subject = $Subject
$message.Body = $emailbody
$smtp = New-Object Net.Mail.SmtpClient($smtpserver)
$smtp.Send($message)

# Clean up log file
Remove-Item $loglocation -Force

关键优化点 #

1. 错误文件夹跟踪：用$errorFolders数组存储删除失败的文件夹EntryID，后续筛选时直接排除，彻底解决无限循环问题
2. 性能优化：每个基文件夹只查询一次完整的文件夹列表，删除子文件夹后仅重新查询父文件夹，大幅降低Exchange服务器负载
3. 完整日志与通知：自动生成日志，清理无用的PowerShell转录头后，将结果邮件发送给IT团队，方便监控
4. 多基文件夹支持：一次运行可处理多个不同的公用文件夹根路径，灵活性拉满

内容来源于stack exchange