CheckDNSRR failing on a valid domain

Hello, I have been trying to use CheckDNSRR and GetMXRR to validate e-mail addresses. I have just realized that these calls fail when checking the top level domain e-na.net . However they succeed on checking www.e-na.net and even point e-na.net as MX host for it. I wonder how could this be because I am able to send a message to addresses like mlemos@e-na.net . Anyway, if these calls may fail this way on valid mail hosts I'm afraid the functions are useless for the purpose of verifying e-mail addresses. Anybody with knowledge in the subject would care to give some light on the matter? Regards, Manuel Lemos Web Programming Components using PHP Classes. Look at: http://phpclasses.UpperDesign.com/?user=mlemos@acm.org -- E-mail: mlemos@acm.org URL: http://www.mlemos.e-na.net/ PGP key: http://www.mlemos.e-na.net/ManuelLemos.pgp --