function Connect-EXO {

    Creates a connection to Exchange online using Oauth
    Acquires a token from Azure AD
    Uses that token to connect to Exchange Online Powershell
    Token lifetime is 1 hour
    The Caller must manage the session / token lifetime.
    It will pull the token from the token cache for a silent refresh of the toke if it is there.
    When the token expires if the session is not refreshed the Exchange shell will attempt implict remoting that will prompt / fail
    None. Creates a PS session to EXO and imports it into the global scope
    Will prompt for credentials and import Exchange PS Session into the global scope

    # Get the token from the service
    $Token = Get-ServiceToken -service exo

    # Build the auth information
    $Authorization = "Bearer {0}" -f $Token.Result.AccessToken
    $UserId = ($Token.Result.UserInfo.DisplayableId).tostring()
    # create the "basic" token to send to O365 EXO
    $Password = ConvertTo-SecureString -AsPlainText $Authorization -Force
    $Credtoken = New-Object System.Management.Automation.PSCredential -ArgumentList $UserId, $Password
    # Create and import the session
    $Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri '' -Credential $Credtoken -Authentication Basic -AllowRedirection -ErrorAction Stop
    Import-Module (Import-PSSession $Session -AllowClobber) -Global