OOF of Distribution List

Autoreply

Install Powershell module,

Install-Module PowershellGet -Force
Install-Module -Name ExchangeOnlineManagement
Connect-ExchangeOnline -UserPrincipalName [e-mail]
Get-DistributionGroup -Identity "DL_Name" | Select SendOofMessageToOriginatorEnabled

Get-DistributionGroup -ResultSize 50000 -WarningAction Ignore | where { $_.SendOofMessageToOriginatorEnabled -eq "True" }