alt Hacker NewsThe only mistake people make here is to accept that the problem is on their end even after Microsoft has accepted the e-mail but silently discarded it. This leads to the customer impression that the mistake happens on their end and not on Microsoft's.
When I see in my logs that the e-mail has been successfully delivered to their MTA then I don't have a problem.
Yep. Let's say for example you were sending a legally important email saying you did something, and your customer tried to sue you over not sending the email. If you sent it and the customer's agent (Microsoft) dropped it, that's a problem between the customer and their agent, and you are not liable.
(If this happens to you, don't admit that you know Microsoft drops your emails, or you'll be liable again!)