migrating-exchange-management-shell

# Migrating the Exchange Management Shell (5.1 → 7.x) The Exchange snap-in (`Microsoft.Exchange.Management.PowerShell.SnapIn`, `.E2010`, `.Admin`) is a binary snap-in that **cannot load in PowerShell 7**. This is the single most common — and hardest — blocker in Exchange-heavy repos. The fix is to stop loading a snap-in and instead **connect to an Exchange endpoint**, which works from any PowerShell edition. ## On-premises Exchange → implicit remoting ```powershell # 5.1 (remove this) Add-PSSnapin Microsoft.Exchange.Management.PowerShell.SnapIn # 7.x — connect to the Exchange remoting endpoint instead $session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri "http://<exchange-server>/PowerShell/" -Authentication Kerberos # or Negotiate Import-PSSession $session -DisableNameChecking -AllowClobber # ... run Exchange cmdlets exactly as before ... Remove-PSSession $session ``` The imported cmdlets keep the same names and parameters, so most script bodies are unchanged. Objects come back **deserialized** — properties survive, methods do not; rewrite any `$mbx.SomeMethod()` calls to use cmdlets. ## Exchange Online → EXO REST module For Exchange Online, do not use WinRM remoting; use the REST-based module (works natively on PS7): ```powershell Install-Module ExchangeOnlineManagement # once Connect-ExchangeOnline -UserPrincipalName admin@contoso.com # ... Exchange Online cmdlets ... Disconnect-ExchangeOnline -Confirm:$false ``` Prefer the `-REST`-backed cmdlets (`Get-EXOMailbox`, `Get-EXORecipient`, …) where available — they are faster and paginate better than the classic aliases. ## Migration steps per script 1. Delete the `Add-PSSnapin Microsoft.Exchange...` line(s). 2. Insert the correct connect block (on-prem remoting vs EXO) near the top. 3. Add the matching disconnect/cleanup at the end (and in a `finally`). 4. Parameterize the endpoint/credentials — do not hardcode servers or secrets. 5. Replace method calls on returned objects with cmdlet equivalents. ## Validation (Rung 4c — the honest limit) Full behavioral parity needs a **live Exchange/EXO environment**, which this agent does not own. Do: - Rung 1/2: parse + PSScriptAnalyzer clean (no snap-in remains). - Prove the **command surface** matches after connecting: ```powershell Get-Command Get-Mailbox | Select-Object -ExpandProperty Parameters ``` Diff against the 5.1 parameter set. - Use `-WhatIf` in a staging org for mutating cmdlets where supported. - Otherwise record `needs-live-env` / `manual-signoff`. Do **not** claim runtime validation that requires infrastructure you cannot reach.