b2.patt-net.dkim.brevo.com has no MX records.
Question and response
Question
dig brevo8.dkim.brevo.com. MX
Answer
The response has no answer records.
Authority
brevo8.dkim.brevo.com. 3600 SOA ns1.sendinblue.com. hostmaster.brevo.com. 2025110802 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0