[Bender]

There's also no indication emails do not reach their destination (no bounced emails so far). Very curios if the email will ultimately be delivered after a resolution is found.

I do not have an account with them but try sending yourself an email from a machine that has FCrDNS and see if the error message is 4xx or 5xx. If 4xx most mail servers will keep the emails in the queue for 2 to 7 days depending on the platform, their volume and other factors. One common exception would be apps just trying to notify you to check something, may or may not have implemented a queue. If the error is in the 5xx range the server is saying the error does not require retrying the message. The specific error message may also give a clue as to what is going on.