sbc1.longlinesvoice.com has no MX records.
Question and response
Question
dig sbc1.longlinesvoice.com. MX
Answer
The response has no answer records.
Authority
longlinesvoice.com. 3600 SOA ns1.longlines.com. scott\.copple.longlines.biz. 758231369 1200 180 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0