mail1.ccsend.com has no MX records.
Question and response
Question
dig mail1.ccsend.com. MX
Answer
The response has no answer records.
Authority
ccsend.com. 2560 SOA ns4.ccsend.com. hostmaster.ccsend.com. 1771763707 16384 2048 1048576 2560
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0