mx1.inbox.lv has no CNAME records.
Question and response
Question
dig mx1.inbox.lv. NS
Answer
The response has no answer records.
Authority
inbox.lv. 3762 SOA ns1.inbox.lv. support.inbox.lv. 2026012300 172800 2048 1048576 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0