iweb1r.iaires.com has no MX records.
Question and response
Question
dig iweb1r.iaires.com. MX
Answer
The response has no answer records.
Authority
iaires.com. 86400 SOA ns1.netcore.co.in. Postmaster.iaires.com. 446618595 900 3600 172800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0