yes, all the records of the domain are pointed to my server.
i did a test on dnsreport.com, and i found this:
Mail FAIL Connect to mail servers ERROR: I could not complete a connection to any of your mailservers!
mail.xb360.nl: Timed out [Last data sent: [Did not connect]]
If this is a timeout problem, note that the DNS report only waits about 30 seconds for responses, so your mail may work fine in this case but you will need to use testing tools specifically designed for such situations.