Exchange Server: ActiveSync / EWS / OWA Ek Boyutu (Attachment) Limitlerini Doğru Artırmak

Bir iletinin/ekin sorunsuz iletilmesi, aynı anda şu katmanların uyumuna bağlıdır:

1. HTTP / IIS / Virtual Directory
   • requestFiltering.requestLimits.maxAllowedContentLength (Byte)
   • httpRuntime.maxRequestLength (KB)
   • (EWS/OWA) WCF bağlayıcıları: maxReceivedMessageSize ve readerQuotas
2. Exchange Transport
   • Kurumsal: Set-TransportConfig -MaxSendSize / -MaxReceiveSize
   • Bağlantılar: Set-SendConnector -MaxMessageSize, Set-ReceiveConnector -MaxMessageSize
   • (Gerekirse) posta kutusu: Set-Mailbox -MaxSendSize -MaxReceiveSize
3. Ağ Cihazları ve İstemci
   • WAF/LB/Reverse Proxy gövde (body) boyutu ve timeout
   • İstemci (mobil/Outlook) sınırları, ara güvenlik ürünleri

Base64 genişlemesi: Ekler MIME/base64 ile ~%33 büyür. 25 MB’lık dosya ~33 MB’ye çıkabilir. Bu yüzden hedefinize %30–40 pay ekleyin.

Varsayılanlara Kısa Bakış (Saha)

• ActiveSync: ~10 MB
• EWS: ~64 MB
• OWA: ~35 MB
  Bunlar IIS ve WCF tarafındaki varsayılanlarla şekillenir; Exchange sürümüne göre küçük farklar olabilir.

Birimlerin Doğru Kullanımı

• maxAllowedContentLength → Byte
• maxRequestLength → KB
• maxReceivedMessageSize → Byte

Hızlı Dönüşüm Tablosu (MiB esaslı)

Tam MiB değerleri kullanmak (1024 tabanlı) hata ayıklamayı kolaylaştırır.

Neden Hem “Default Web Site” Hem “Exchange Back End”?

Exchange 2013/2016/2019’da Front-End (Default Web Site) proxy, Back-End (Exchange Back End) ise iş mantığını yürütür. Bu yüzden her iki tarafta da ilgili sanal dizinin limitlerini yükseltmelisiniz.

Komutlarla Artırma (appcmd)

Önemli: Komutları Yönetici CMD’de tek tek çalıştırın. Değerleri kendi hedefinize göre güncelleyin. Bitince IIS’i yeniden başlatın.

1. ActiveSync (Microsoft-Server-ActiveSync) – Örnek ~66.5 MiB

%windir%\system32\inetsrv\appcmd.exe set config "Default Web Site/Microsoft-Server-ActiveSync/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:69730304
%windir%\system32\inetsrv\appcmd.exe set config "Default Web Site/Microsoft-Server-ActiveSync/" -section:system.web/httpRuntime /maxRequestLength:68096

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/Microsoft-Server-ActiveSync/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:69730304
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/Microsoft-Server-ActiveSync/" -section:system.web/httpRuntime /maxRequestLength:68096
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/Microsoft-Server-ActiveSync/" -section:appSettings /[key='MaxDocumentDataSize'].value:69730304

• requestFiltering (Byte) ve httpRuntime (KB) birlikte artırılır.
• MaxDocumentDataSize EAS özelidir (Byte).

2. EWS (Exchange Web Services) – Örnek 64 MB

%windir%\system32\inetsrv\appcmd.exe set config "Default Web Site/ews/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:67108864

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:67108864

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSAnonymousHttpsBinding'].httpsTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSAnonymousHttpBinding'].httpTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSBasicHttpsBinding'].httpsTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSBasicHttpBinding'].httpTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSNegotiateHttpsBinding'].httpsTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSNegotiateHttpBinding'].httpTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSWSSecurityHttpsBinding'].httpsTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSWSSecurityHttpBinding'].httpTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSWSSecuritySymmetricKeyHttpsBinding'].httpsTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSWSSecuritySymmetricKeyHttpBinding'].httpTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSWSSecurityX509CertHttpsBinding'].httpsTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSWSSecurityX509CertHttpBinding'].httpTransport.maxReceivedMessageSize:67108864

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /webHttpBinding.[name='EWSStreamingNegotiateHttpsBinding'].maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /webHttpBinding.[name='EWSStreamingNegotiateHttpBinding'].maxReceivedMessageSize:67108864

• WCF bağlayıcıları (hem HTTP hem HTTPS) tek tek yükseltilir.
• Streaming bağlayıcıları da unutmayın.

3. OWA (Outlook on the web) – Örnek 35 MB

%windir%\system32\inetsrv\appcmd.exe set config "Default Web Site/owa/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:35000000
%windir%\system32\inetsrv\appcmd.exe set config "Default Web Site/owa/" -section:system.web/httpRuntime /maxRequestLength:35000

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/owa/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:35000000
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/owa/" -section:system.web/httpRuntime /maxRequestLength:35000

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/owa/" -section:system.serviceModel/bindings /webHttpBinding.[name='httpsBinding'].maxReceivedMessageSize:35000000
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/owa/" -section:system.serviceModel/bindings /webHttpBinding.[name='httpBinding'].maxReceivedMessageSize:35000000
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/owa/" -section:system.serviceModel/bindings /webHttpBinding.[name='httpsBinding'].readerQuotas.maxStringContentLength:35000000
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/owa/" -section:system.serviceModel/bindings /webHttpBinding.[name='httpBinding'].readerQuotas.maxStringContentLength:35000000

Tam 35 MiB istersen Byte değerini 36 700 160 kullan.

4. IIS Yeniden Başlatma

net stop w3svc /y
net start w3svc

Alternatif: iisreset /noforce veya ilgili App Pool’ları recycle.

Transport Katmanını Eşitleyin (Aksi Hâlde Mesaj Yine Düşer)

# Organizasyon genel
Set-TransportConfig -MaxSendSize 100MB -MaxReceiveSize 100MB

# Bağlantılar
Set-SendConnector    "Internet Out"           -MaxMessageSize 100MB
Set-ReceiveConnector "Default Frontend EX01"  -MaxMessageSize 100MB

# (Gerekirse) belirli posta kutuları
Set-Mailbox user@domain.com -MaxSendSize 100MB -MaxReceiveSize 100MB

Karşı tarafın (alıcı sistem) limitleri de nihai teslimi belirler.

WAF / LB / Reverse Proxy Ayarları – Büyük Ekler ve Uzun Bağlantılar

• Body size: WAF/LB varsayılanları (NGINX client_max_body_size, F5/HAProxy vb.) büyük yüklemeleri 413/502/504 ile kesebilir. Sunucu hedefinize uyacak şekilde ≥ hedef+%40 ayarlayın (ör. 100 MB).
• Idle timeout: MAPI/HTTP ve EWS uzun bağlantılar kurar. LB idle timeout’u ≥ 15 dk (900 sn) olmalı (tercihen 1800 sn).
• Header’lar: X-Forwarded-For/Proto geçsin; Host başlığı orijinal FQDN kalsın.
• SSL re-encrypt (bridging) önerilir: Hem WAF denetimi, hem iç ağda şifreli trafik.

Doğrulama – Ne, Nerede Kontrol Edilir?

1. Tarayıcı/İstemci Testleri
   • OWA’dan hedef boyutta ek yüklemeyi deneyin.
   • Mobilde (EAS) aynı boyutta gönderim yapın.
   • EWS kullanan uygulama/servislerle test edin.
2. IIS Logları
   • Varsayılan yollar:
     • C:\inetpub\logs\LogFiles\W3SVC1 (Default Web Site)
     • C:\inetpub\logs\LogFiles\W3SVC2 (Exchange Back End)
   • 404.13 → requestFiltering limiti küçük
   • “Maximum request length exceeded.” → httpRuntime küçük
3. Uygulama Günlükleri / Event Viewer
   • Application / MSExchange günlükleri
   • WCF quota uyarıları → maxReceivedMessageSize / readerQuotas
4. Mevcut Değerleri Listeleme

%windir%\system32\inetsrv\appcmd.exe list config "Default Web Site/ews/" -section:system.webServer/security/requestFiltering
%windir%\system32\inetsrv\appcmd.exe list config "Default Web Site/ews/" -section:system.web/httpRuntime
%windir%\system32\inetsrv\appcmd.exe list config "Exchange Back End/ews/" -section:system.serviceModel/bindings

Çok Sunuculu Ortamlarda;

• Ayarları tüm CAS/MBX sunucularında tekrarlayın.
• Otomasyon önerisi: PowerShell ile Invoke-Command veya PS Remoting kullanarak aynı komutları birden fazla sunucuya gönderin.
• Load balancer arkasında, node’ları drain alarak kesintisiz uygulayın.

CU (Cumulative Update) Sonrası Yeniden Uygulamak Gerekecektir

Exchange CU yüklemeleri sırasında web.config/app.config ve IIS’e yazdığınız özelleştirmelerin bir kısmı ezilebilir.

• Dokümante edin: Uyguladığınız tüm değerleri kaydedin.
• CU sonrası bir script ile tekrar uygulayın.
• Gerekirse C:\inetpub\history’de IIS config geçmişi ve değişiklik karşılaştırmaları işinizi kolaylaştırır.

Sık Hata → Hızlı Yol Haritası

Bu PowerShell Scirpt’i ile ActiveSync, EWS ve OWA için IIS tarafındaki tüm ilgili limitleri (Byte/KB/WCF), tüm Exchange sunucularına uzaktan uygular, istersen Transport katmanındaki boyut sınırlarını da senkronize eder. MiB tabanlı (1024) hassas hesap yapar DryRun (plan/önizleme) ve IIS reset opsiyonu içerir.

<#
.SYNOPSIS
  Exchange Server – ActiveSync/EWS/OWA ek (attachment) ve istek boyutu limitlerini
  IIS (Front-End & Back-End) + WCF üzerinde parametrik olarak yükseltir.
  İsteğe bağlı: Transport (org/connector/mailbox) limitlerini de senkronize eder.

.EXAMPLE
  .\Set-ExchangeAttachmentLimits.ps1 -Servers EX01,EX02 -EasMB 70 -EwsMB 64 -OwaMB 35 `
    -ApplyTransport -TransportMaxMB 100 -SendConnector "Internet Out" `
    -ReceiveConnectors "Default Frontend EX01","Default Frontend EX02"

.EXAMPLE (Dry run)
  .\Set-ExchangeAttachmentLimits.ps1 -Servers EX01 -EasMB 50 -EwsMB 64 -OwaMB 35 -DryRun
#>

[CmdletBinding(SupportsShouldProcess=$true)]
param(
  [Parameter(Mandatory=$false)]
  [string[]]$Servers = @($env:COMPUTERNAME),

  [Parameter(Mandatory=$false)]
  [int]$EasMB = 70,                  # Microsoft-Server-ActiveSync hedef MiB

  [Parameter(Mandatory=$false)]
  [int]$EwsMB = 64,                  # EWS hedef MiB

  [Parameter(Mandatory=$false)]
  [int]$OwaMB = 35,                  # OWA hedef MiB

  [Parameter(Mandatory=$false)]
  [int]$TransportMaxMB = 100,        # Transport/Connector/Mailbox için hedef MiB

  [Parameter(Mandatory=$false)]
  [string]$SendConnector = $null,    # Örn: "Internet Out"

  [Parameter(Mandatory=$false)]
  [string[]]$ReceiveConnectors = @(),# Örn: "Default Frontend EX01","Default Frontend EX02"

  [Parameter(Mandatory=$false)]
  [string[]]$Mailboxes = @(),        # İsteğe bağlı: belirli mailbox’lar için sınır

  [Parameter(Mandatory=$false)]
  [string]$FrontEndSite = "Default Web Site",

  [Parameter(Mandatory=$false)]
  [string]$BackEndSite  = "Exchange Back End",

  [Parameter(Mandatory=$false)]
  [switch]$ApplyTransport,           # Transport tarafını da uygula

  [Parameter(Mandatory=$false)]
  [switch]$SkipIISReset,             # IIS reset istemiyorsan işaretle

  [Parameter(Mandatory=$false)]
  [switch]$DryRun,                   # Sadece plan/önizleme yap

  [Parameter(Mandatory=$false)]
  [System.Management.Automation.PSCredential]$Credential
)

function Convert-ToBytes([int]$mb) { return [int64]$mb * 1MB } # 1MB = 1048576 byte
function Convert-ToKB   ([int]$mb) { return [int]  $mb * 1024 }

$EasBytes = Convert-ToBytes $EasMB; $EasKB = Convert-ToKB $EasMB
$EwsBytes = Convert-ToBytes $EwsMB
$OwaBytes = Convert-ToBytes $OwaMB; $OwaKB = Convert-ToKB $OwaMB

Write-Host "== Plan ==" -ForegroundColor Cyan
"{0,-18}: {1,6} MiB  -> {2,10} KB | {3,12} Bytes" -f "ActiveSync (EAS)", $EasMB, $EasKB, $EasBytes
"{0,-18}: {1,6} MiB  -> {2,10} KB | {3,12} Bytes" -f "EWS",             $EwsMB, (Convert-ToKB $EwsMB), $EwsBytes
"{0,-18}: {1,6} MiB  -> {2,10} KB | {3,12} Bytes" -f "OWA",             $OwaMB, $OwaKB, $OwaBytes
if ($ApplyTransport) {
  "{0,-18}: {1,6} MiB" -f "Transport", $TransportMaxMB | Write-Host
}
"Sunucular: {0}" -f ($Servers -join ", ") | Write-Host
if ($DryRun) { Write-Warning "DryRun aktif: komutlar uygulanmayacak, sadece gösterilecektir." }

# -- Uzakta çalışacak script block (IIS + WCF ayarları) --
$scriptBlock = {
  param($FrontEndSite,$BackEndSite,$EasBytes,$EasKB,$EwsBytes,$OwaBytes,$OwaKB,$DryRun)

  $appcmd = "$env:windir\system32\inetsrv\appcmd.exe"
  if (-not (Test-Path $appcmd)) { throw "appcmd.exe bulunamadı: $appcmd" }

  function Run-Cmd {
    param([string]$cmdLine)
    Write-Host " > $cmdLine"
    if (-not $DryRun) {
      cmd.exe /c $cmdLine | Out-Host
      if ($LASTEXITCODE -ne 0) { throw "Komut hata ile döndü: $cmdLine" }
    }
  }

  Write-Host "== [$env:COMPUTERNAME] ActiveSync =="
  Run-Cmd "`"$appcmd`" set config `"$FrontEndSite/Microsoft-Server-ActiveSync/`" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:$EasBytes"
  Run-Cmd "`"$appcmd`" set config `"$FrontEndSite/Microsoft-Server-ActiveSync/`" -section:system.web/httpRuntime /maxRequestLength:$EasKB"

  Run-Cmd "`"$appcmd`" set config `"$BackEndSite/Microsoft-Server-ActiveSync/`" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:$EasBytes"
  Run-Cmd "`"$appcmd`" set config `"$BackEndSite/Microsoft-Server-ActiveSync/`" -section:system.web/httpRuntime /maxRequestLength:$EasKB"
  Run-Cmd "`"$appcmd`" set config `"$BackEndSite/Microsoft-Server-ActiveSync/`" -section:appSettings /[key='MaxDocumentDataSize'].value:$EasBytes"

  Write-Host "== [$env:COMPUTERNAME] EWS =="
  Run-Cmd "`"$appcmd`" set config `"$FrontEndSite/ews/`" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:$EwsBytes"
  Run-Cmd "`"$appcmd`" set config `"$BackEndSite/ews/`" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:$EwsBytes"

  $ewsBindings = @(
    'EWSAnonymousHttpsBinding','EWSAnonymousHttpBinding',
    'EWSBasicHttpsBinding','EWSBasicHttpBinding',
    'EWSNegotiateHttpsBinding','EWSNegotiateHttpBinding',
    'EWSWSSecurityHttpsBinding','EWSWSSecurityHttpBinding',
    'EWSWSSecuritySymmetricKeyHttpsBinding','EWSWSSecuritySymmetricKeyHttpBinding',
    'EWSWSSecurityX509CertHttpsBinding','EWSWSSecurityX509CertHttpBinding'
  )

  foreach ($b in $ewsBindings) {
    if ($b -like '*HttpsBinding') {
      Run-Cmd "`"$appcmd`" set config `"$BackEndSite/ews/`" -section:system.serviceModel/bindings /customBinding.[name='$b'].httpsTransport.maxReceivedMessageSize:$EwsBytes"
    } else {
      Run-Cmd "`"$appcmd`" set config `"$BackEndSite/ews/`" -section:system.serviceModel/bindings /customBinding.[name='$b'].httpTransport.maxReceivedMessageSize:$EwsBytes"
    }
  }

  Run-Cmd "`"$appcmd`" set config `"$BackEndSite/ews/`" -section:system.serviceModel/bindings /webHttpBinding.[name='EWSStreamingNegotiateHttpsBinding'].maxReceivedMessageSize:$EwsBytes"
  Run-Cmd "`"$appcmd`" set config `"$BackEndSite/ews/`" -section:system.serviceModel/bindings /webHttpBinding.[name='EWSStreamingNegotiateHttpBinding'].maxReceivedMessageSize:$EwsBytes"

  Write-Host "== [$env:COMPUTERNAME] OWA =="
  Run-Cmd "`"$appcmd`" set config `"$FrontEndSite/owa/`" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:$OwaBytes"
  Run-Cmd "`"$appcmd`" set config `"$FrontEndSite/owa/`" -section:system.web/httpRuntime /maxRequestLength:$OwaKB"

  Run-Cmd "`"$appcmd`" set config `"$BackEndSite/owa/`" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:$OwaBytes"
  Run-Cmd "`"$appcmd`" set config `"$BackEndSite/owa/`" -section:system.web/httpRuntime /maxRequestLength:$OwaKB"
  Run-Cmd "`"$appcmd`" set config `"$BackEndSite/owa/`" -section:system.serviceModel/bindings /webHttpBinding.[name='httpsBinding'].maxReceivedMessageSize:$OwaBytes"
  Run-Cmd "`"$appcmd`" set config `"$BackEndSite/owa/`" -section:system.serviceModel/bindings /webHttpBinding.[name='httpBinding'].maxReceivedMessageSize:$OwaBytes"
  Run-Cmd "`"$appcmd`" set config `"$BackEndSite/owa/`" -section:system.serviceModel/bindings /webHttpBinding.[name='httpsBinding'].readerQuotas.maxStringContentLength:$OwaBytes"
  Run-Cmd "`"$appcmd`" set config `"$BackEndSite/owa/`" -section:system.serviceModel/bindings /webHttpBinding.[name='httpBinding'].readerQuotas.maxStringContentLength:$OwaBytes"

  Write-Host "== [$env:COMPUTERNAME] TAMAMLANDI ==" -ForegroundColor Green
}

# -- IIS & WCF uygulaması: tüm hedef sunucular --
foreach ($srv in $Servers) {
  Write-Host "`n### Sunucu: $srv" -ForegroundColor Yellow
  try {
    if ($PSBoundParameters.ContainsKey('Credential')) {
      Invoke-Command -ComputerName $srv -Credential $Credential -ScriptBlock $scriptBlock `
        -ArgumentList $FrontEndSite,$BackEndSite,$EasBytes,$EasKB,$EwsBytes,$OwaBytes,$OwaKB,$DryRun
    } else {
      Invoke-Command -ComputerName $srv -ScriptBlock $scriptBlock `
        -ArgumentList $FrontEndSite,$BackEndSite,$EasBytes,$EasKB,$EwsBytes,$OwaBytes,$OwaKB,$DryRun
    }

    if (-not $SkipIISReset -and -not $DryRun) {
      Write-Host "IIS reset ($srv)..." -ForegroundColor DarkCyan
      if ($PSBoundParameters.ContainsKey('Credential')) {
        Invoke-Command -ComputerName $srv -Credential $Credential -ScriptBlock { iisreset /noforce | Out-Host }
      } else {
        Invoke-Command -ComputerName $srv -ScriptBlock { iisreset /noforce | Out-Host }
      }
    }

  } catch {
    Write-Error "[$srv] hata: $_"
  }
}

# -- Transport katmanı (opsiyonel) --
if ($ApplyTransport) {
  Write-Host "`n== Transport Senkronizasyonu ==" -ForegroundColor Cyan
  # Exchange cmdlet’leri hazır mı?
  if (-not (Get-Command Set-TransportConfig -ErrorAction SilentlyContinue)) {
    Write-Warning "Exchange PowerShell modülleri yüklü değil gibi görünüyor. Transport adımı atlanıyor."
  } else {
    if ($PSCmdlet.ShouldProcess("TransportConfig","Set-TransportConfig")) {
      if ($DryRun) {
        Write-Host " > Set-TransportConfig -MaxSendSize ${TransportMaxMB}MB -MaxReceiveSize ${TransportMaxMB}MB"
      } else {
        Set-TransportConfig -MaxSendSize ("{0}MB" -f $TransportMaxMB) -MaxReceiveSize ("{0}MB" -f $TransportMaxMB)
      }
    }
    if ($SendConnector) {
      if ($PSCmdlet.ShouldProcess("SendConnector:$SendConnector","Set-SendConnector")) {
        if ($DryRun) {
          Write-Host " > Set-SendConnector `"$SendConnector`" -MaxMessageSize ${TransportMaxMB}MB"
        } else {
          Set-SendConnector $SendConnector -MaxMessageSize ("{0}MB" -f $TransportMaxMB)
        }
      }
    }
    foreach ($rc in $ReceiveConnectors) {
      if ($PSCmdlet.ShouldProcess("ReceiveConnector:$rc","Set-ReceiveConnector")) {
        if ($DryRun) {
          Write-Host " > Set-ReceiveConnector `"$rc`" -MaxMessageSize ${TransportMaxMB}MB"
        } else {
          Set-ReceiveConnector $rc -MaxMessageSize ("{0}MB" -f $TransportMaxMB)
        }
      }
    }
    foreach ($mbx in $Mailboxes) {
      if ($PSCmdlet.ShouldProcess("Mailbox:$mbx","Set-Mailbox")) {
        if ($DryRun) {
          Write-Host " > Set-Mailbox $mbx -MaxSendSize ${TransportMaxMB}MB -MaxReceiveSize ${TransportMaxMB}MB"
        } else {
          Set-Mailbox $mbx -MaxSendSize ("{0}MB" -f $TransportMaxMB) -MaxReceiveSize ("{0}MB" -f $TransportMaxMB)
        }
      }
    }
  }
}

Write-Host "`n== BİTTİ ==" -ForegroundColor Green
Write-Host "Not: Exchange CU sonrası web.config/IIS özelleştirmeleri ezilebilir; bu betiği CU’dan sonra tekrar çalıştırın."

Kullanım önerileri

• Tüm CAS/MBX node’larında IIS/WCF limitlerini uygula + Transport’u senkronize et:

.\Set-ExchangeAttachmentLimits.ps1 `
  -Servers EX01,EX02 `
  -EasMB 70 -EwsMB 64 -OwaMB 35 `
  -ApplyTransport -TransportMaxMB 100 `
  -SendConnector "Internet Out" `
  -ReceiveConnectors "Default Frontend EX01","Default Frontend EX02"

• Önizleme (DryRun):

.\Set-ExchangeAttachmentLimits.ps1 -Servers EX01 -EasMB 50 -EwsMB 64 -OwaMB 35 -DryRun

• IIS reset’i atla (bakım penceresinde manuel yapacaksan):

.\Set-ExchangeAttachmentLimits.ps1 -Servers EX01,EX02 -EasMB 70 -EwsMB 64 -OwaMB 35 -SkipIISReset

İpucu: MIME/base64 genişlemesi nedeniyle hedef ek boyutunuzun %30–40 üstünü limit olarak verin (ör. 25 MB hedef için ~35 MB). CU (Cumulative Update) sonrasında bu betiği tekrar çalıştırmayı unutmayın.