Most used commands for Exchange Online

Install Exchange Online powershell module

Install-Module -Name ExchangeOnlineManagement

Connect to Exchange Online

Import-Module ExchangeOnlineManagement

Connect-ExchangeOnline -UserPrincipalName admin@company.onmicrosoft.com

Get deleted mailboxes

Source:

https://learn.microsoft.com/en-us/powershell/exchange/connect-to-exchange-online-powershell?view=exchange-ps