lexis.com has no MX records.
Question and response
Question
dig lexis.com. MX
Answer
The response has no answer records.
Authority
lexis.com. 900 SOA spn5061.telecom.regn.net. hostmaster.lexisnexis.com. 1586 3600 900 2419200 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0