Collegarsi ad Office 365 tramite powershell (with or w/o MFA)

Per collegarsi in powershell senza MFA (multifactor authentication)

Aprire powershell in administrative mode

Set-ExecutionPolicy -executionpolicy Unrestricted

$UserCredential = Get-Credential
apparira una finestra in cui inserire le credenziali di accesso al tenant

Oppure

$UserCredential = Get-Credential postmaster@tenantname.onmicrosoft.com
 (verra richiesta la password)

$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
Con questo comando viene creata la sessione

Import-PSSession $Session

Oppure

Import-PSSession $Session -DisableNameChecking

con questo comando si avvia la sessione

Remove-PSSession $Session
Ricordarsi di chiudere la sessione, una volta concluso.

Esiste un limite di sessioni. Una volta raggiunto questo limite non e' possibile crearne di nuove. Per collegarsi occorre aspettare che quelle occupate vadano in timeout

Get-pssession
mostra le sessioni attive in questo momento

Collegarsi ad Office365 in Powershell con MFA
Aprire il browser (come administrator), andare nell'interfaccia di gestione di Exchange online - in Hybrid e premere su powershell. 
A questo punto si aprira la powershell. Se abbiamo aperto il browser come administrator, si aprira la powershell come administrator.
Eseguire il  seguente comendo:

Connect-EXOPSSession [-UserPrincipalName -ConnectionUri <ConnectionUri> -AzureADAuthorizationEndPointUri <AzureADUri> -DelegatedOrganization <String>]
Connect-EXOPSSession -UserPrincipalName user@domain.onmicrosoft.com


REFERENCE
https://docs.microsoft.com/it-it/powershell/exchange/exchange-online/connect-to-exchange-online-powershell/mfa-connect-to-exchange-online-powershell?view=exchange-ps
https://docs.microsoft.com/en-us/powershell/exchange/exchange-online/connect-to-exchange-online-powershell/connect-to-exchange-online-powershell?redirectedfrom=MSDN&view=exchange-ps

https://github.com/MicrosoftDocs/office-docs-powershell/blob/master/exchange/docs-conceptual/exchange-online/connect-to-exchange-online-powershell/mfa-connect-to-exchange-online-powershell.md
https://www.petenetlive.com/KB/Article/0001410

https://docs.microsoft.com/en-us/powershell/exchange/exchange-online/connect-to-exchange-online-powershell/connect-to-exchange-online-powershell?view=exchange-ps
https://docs.microsoft.com/en-us/powershell/exchange/exchange-online/disable-access-to-exchange-online-powershell?view=exchange-ps
https://www.solvitns.com.au/how-to-connect-disconnect-to-office-365-with-powershell/