Hi. I’m getting email deliverability issues to Microsoft Exchange. Here is the return error (I have removed my domain names from the below examples):
That user is a new Exchange test account that I have set up and it accepts other emails from domains including Gmail, Hotmail etc.
For info, I have also had problems sending to older Microsoft Exchange accounts too, but bizarrely not Live.co.uk or Hotmail addresses.
I have gone through extensive MXToolbox testing and have SPF, DKIM, DMARC correctly set up on my account and other recipients receive my emails fine.
I think that my problem is probably that I have the _dc-mx.12345678.mydomain as a hostname that resolves to my server’s IP address.
I have looked into this and the only resolution I can see on Cloudflare is to set these records:
MX mydomain mail.mydomain
A mail 192.168.0.2 <= (My server IP)
I have been using this (for several months) but with the same problem.
My actual mail server is on the same Server IP as my domain but it has a different name:
There is no orange cloud on anything except my domain and the www Cname.
I have tested my server IP and domain against the Microsoft ‘unblock’ form and it says neither is being blocked.
Any solutions or ideas are very welcome as I’m tearing my hair out at this point.