eu3.userecho.com has no MX records.
Question and response
Question
dig eu3.userecho.com. MX
Answer
The response has no answer records.
Authority
userecho.com. 600 SOA ns.us4.stamul.com. info.userecho.com. 1257588811 1200 300 1209600 38400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0