mail.pasty.com has no MX records.
Question and response
Question
dig mail.pasty.com. MX
Answer
The response has no answer records.
Authority
pasty.com. 2560 SOA ns1.pasty.net. hostmaster.pasty.net. 2025111600 28800 7200 1604800 86400
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0