www.openhouse.org has no MX records.
Question and response
Question
dig www.openhouse.org. MX
Answer
The response has no answer records.
Authority
www.openhouse.org. 3600 SOA ns1.parkingcrew.net. hostmaster.www.openhouse.org. 1771952523 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0