mail.reic-rcs.com has no MX records.
Question and response
Question
dig mail.reic-rcs.com. MX
Answer
The response has no answer records.
Authority
reic-rcs.com. 86400 SOA ns1.reic-rcs.com. root.reic-rcs.com. 1002 10800 900 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0