Hello Kyle,
Many thanks for your reply.
Our server is GoDaddy with cPanel installed, IP - 160.153.234.221, email info[at]wetroomstop.com
I have tested it by sending to my private hotmail accounts, but we can also notice that with our clients not getting our emails (then we need to help ourselves with our Gmail account).
We don't seem to have any problems with anything beside microsoft domains. We did everything we could from the servers perspective according to cPanel support.
Submitting a delisting request only allows to insert one email address, while it appears as our entire domain is blocked.
Looking forward to help, we do encounter the same problem with numerous other servers and domains with same conf, if we manage to sort it our with this one, I will apply the same to the other domains.