Unable to send Spaces Invitation Email for testing

Hi! 

 I am trying to test out Spaces welcome email that a customer will receive. I have gone into the backend to try sending the email to several different email addresses (my work email and personal email and tried resending it to internal users who already have access) and when I click “send” I continue to get the “unable to send email at this time” error message. I have gotten this a few times the last couple of days. 

Is there something I am doing wrong? The same error happened when our GS admin tested it to try to send to me as well. 

Thanks