mail.premiumwebservers.com has no SRV records.
Question and response
Question
dig mail.premiumwebservers.com. SRV
Answer
The response has no answer records.
Authority
premiumwebservers.com. 3600 SOA nxg9180.premiumwebservers.com. hostmaster.premiumwebservers.com. 132 900 600 86400 3600
Additional
. 0 OPT ; payload 4000, xrcode 0, version 0, flags 0