mail.brilliantnavigator.com has no SRV records.
Question and response
Question
dig mail.brilliantnavigator.com. SRV
Answer
The response has no answer records.
Authority
brilliantnavigator.com. 3600 SOA ns1.loopia.se. registry.loopia.se. 1772064000 14400 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0