# Get AD users within specified group
$group = "ADgroup"

# Extract AD users' email addresses from group
$adUsers = Get-ADGroup -Filter {Name -like $group} | Get-ADGroupMember - Recursive |
Select-Object -Unique |
Get-ADUser -Properties Mail |
Select-Object Mail |
Sort-Object Mail

# Get users in "Owners" group with site title
$sites = Get-SPOSite -Limit All | Where-Object {$_.Url -like "https://contoso.sharepoint.com/sites*"} # Only store site collections in variable

# Get site owners and site title
$owners = ForEach ($site in $sites)
{
    $site | Select-Object -ExpandProperty Title
    Get-SPOSiteGroup $site | Where {$_.Group -like "*Owners*"} | Select-Object -ExpandProperty Users
}

# Check if site owner is in AD users list
If ($adUsers.Mail | Where-Object {$owners -contains $_})
{
    Write-Host $owners
}
Else {
    Write-Host "No user in distribution list is owner of the specified site(s)."
}