Originally Posted by Showa
According to them I have this in my MX and A records:
mydomain.com MX 10 smpt.mydomain.com
mydomain.com MX 20 mailrelay.planet.nl
smpt.mydomain.nl A my ip-adress
I think you have forgotten the trailing dots in your records. They should be as follows:
mydomain.com. MX 10 smpt.mydomain.com.
mydomain.com. MX 20 mailrelay.planet.nl.
smpt.mydomain.nl. A my ip-adress