# https://www.reddit.com/r/PowerShell/comments/ti6ukx/weird_issue_with_no_solution/
# must have impersonation access
# https://cloudsolutions.atlassian.net/wiki/spaces/CKB/pages/4358166/Setting+up+Application+Impersonation+for+Exchange+or+Office+365#:~:text=Login%20to%20the%20Office%20365,Name%20and%20Description%20'CloudMigratorImpersonation'.&text=Click%20'Save'%20in%20the%20',role%20listed%20in%20Admin%20Roles.

$user = '<adminemail>'
$pass = '<adminpass>'

$mailboxtoimpersonate = '<[email protected]>'

Add-Type -Path 'C:\Program Files\Microsoft\Exchange\Web Services\2.2\Microsoft.Exchange.WebServices.dll'
$ExchangeVersion = [Microsoft.Exchange.WebServices.Data.ExchangeVersion]::Exchange2013_SP1
$service = New-Object Microsoft.Exchange.WebServices.Data.ExchangeService($ExchangeVersion)
$service.Credentials = New-Object System.Net.NetworkCredential($user, $pass)
$Provider=New-Object Microsoft.CSharp.CSharpCodeProvider
$Compiler=$Provider.CreateCompiler()
$Params=New-Object System.CodeDom.Compiler.CompilerParameters
$Params.GenerateExecutable=$False
$Params.GenerateInMemory=$True
$Params.IncludeDebugInformation=$False
$Params.ReferencedAssemblies.Add("System.DLL") | Out-Null
$TASource=@'
  namespace Local.ToolkitExtensions.Net.CertificatePolicy{
    public class TrustAll : System.Net.ICertificatePolicy {
      public TrustAll() {
      }
      public bool CheckValidationResult(System.Net.ServicePoint sp,
        System.Security.Cryptography.X509Certificates.X509Certificate cert,
        System.Net.WebRequest req, int problem) {
        return true;
      }
    }
  }
'@
$TAResults=$Provider.CompileAssemblyFromSource($Params,$TASource)
$TAAssembly=$TAResults.CompiledAssembly
$TrustAll=$TAAssembly.CreateInstance("Local.ToolkitExtensions.Net.CertificatePolicy.TrustAll")
[System.Net.ServicePointManager]::CertificatePolicy=$TrustAll
$uri=[system.URI] 'https://outlook.office365.com/ews/exchange.asmx'
$service.Url = $uri

# Get last email from mailbox
$service.ImpersonatedUserId = new-object Microsoft.Exchange.WebServices.Data.ImpersonatedUserId([Microsoft.Exchange.WebServices.Data.ConnectingIdType]::SmtpAddress, $mailboxtoimpersonate)
$inbox = [Microsoft.Exchange.WebServices.Data.Folder]::Bind($service, [Microsoft.Exchange.WebServices.Data.WellKnownFolderName]::Inbox)
$mails = $inbox.FindItems(10000)

# really only need to load however many emails you want to check
#$mails | select -f 5 | % {$_.Load()}
$mails | % {$_.Load()}

# testing
#$from = $mails.Items[0].Sender.address
#$date = $mails.Items[0].DateTimeReceived.ToString()
#$message = '' | select @{n='from';e={$from}}, @{n='date';e={$date}}

# body of most recent email
$mails.items[0].body.text