redmine.recombo.com has no MX records.
Question and response
Question
dig redmine.recombo.com. MX
Answer
The response has no answer records.
Authority
recombo.com. 3600 SOA ns1.webnames.ca. postmaster.webnames.ca. 1683561681 1200 180 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0