tiger.r1servers.com has no MX records.
Question and response
Question
dig tiger.r1servers.com. MX
Answer
The response has no answer records.
Authority
r1servers.com. 360 SOA ns1.fox.r1servers.com. office.hostbulgaria.com. 2026010303 21600 600 1209600 360
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0