PowerShell and other very useful links

Azure Active Directory: Automating Guest User Management

• https://devblogs.microsoft.com/premier-developer/azure-active-directory-automating-guest-user-management/

MonitorInactiveGuestAccounts.ps1

• https://dev.azure.com/francislacroix/_git/CodeShare?path=%2FGuestUserAutomationBlog%2FMonitorInactiveGuestAccounts.ps1

You do not have the permission to send the message on behalf of the specified user

• https://www.admin-enclave.com/en/articles/exchange/292-resolved-you-do-not-have-the-permission-to-send-the-message-on-behalf-of-the-specified-user.html

CodeTwo Free Tools

https://www.codetwo.com/downloads/freeware/

Setting an auto reply for a distribution group

https://www.codetwo.com/admins-blog/setting-an-autoreply-for-a-distribution-group/