mail11515.email.campaignengine.io has no MX records.
Question and response
Question
dig mail11515.email.campaignengine.io. MX
Answer
The response has no answer records.
Authority
campaignengine.io. 3600 SOA ns8.wixdns.net. support.wix.com. 2025050114 10800 3600 1209600 3600
Additional
. 0 OPT ; payload 512, xrcode 0, version 0, flags 0