Just a simple one-liner When you have many room mailboxes, granting someone access to each room calendar one-by-one is painful. This one-liner reads a list of room SMTP addresses from a text file and applies the same permission to each mailbox calendar. 1 2 3 4 5 Get-Content .\rooms.txt | % { Write-Host "Working on $_" -ForegroundColor Cyan Add-MailboxFolderPermission -Identity "$($_.Trim()):\Calendar" -User "[email protected]" -AccessRights Reviewer } Notes Text file we import via Get-Content contains a room email address per line .Trim is being used to remove blank spaces in TXT file - (’ [email protected]’ -> ‘[email protected]’) - it’s just a safety feature I like to use In some tenants, the calendar folder name might be localized (for example “Kalendarz” in Poland, “Kalender” in Germany and “Calendier” for France) If permissions are already granted for an user, you need to either remove these and re-add or use Set-MailboxFolderPermissions

The easy part Creating distribution lists in bulk is quite simple. Just a CSV file: 1 2 3 4 name,mail Fancy Group,[email protected] Another Fancy Group,[email protected] Not That Fancy Group,[email protected] And for-each loop 1 2 3 4 5 6 7 Import-Csv .\groups.csv | ForEach-Object { New-DistributionGroup -Name $_.name -PrimarySmtpAddress $_.mail -OrganizationalUnit 'OU=Groups,DC=wrong,DC=went,DC=something,DC=dev' -Type Security } Result: Name DisplayName GroupType PrimarySmtpAddress Fancy Group Fancy Group Universal, SecurityEnabled [email protected] Another Fancy Group Another Fancy Group Universal, SecurityEnabled [email protected] Not That Fancy Group Not That Fancy Group Universal, SecurityEnabled [email protected] But updating msExchExtensionAttribute is different A below won’t work as there is no such command under Set-DistributionGroup. ...

<# .SYNOPSIS Adds users from a TXT file to an Entra ID Group via Microsoft Graph. .DESCRIPTION The script reads UPNs from a text file, resolves each user (first by UPN, then by mail as fallback), and adds them to the specified group. Works with both Security Groups and Microsoft 365 Groups. .PARAMETER GroupId Object ID of the target Entra ID Group. .PARAMETER FilePath Path to the TXT file containing one UPN per line. ...