I moved our nameservers from virtual hosting to our new server. I set up bind 9.8, copied all settings, and it almost works.
when I use my local provider dns or google's, I get correct results.
but some internet providers and services like iCloud outlook.com and yahoo can't resolve the domain.
emails return after few days with the error "can't resolve mx or a record" but I can still receive email from gmail.
I even tried setting up dnssec but nothing seems to help.
the domain is sonic.sk - nameservers ns1.sonik.sk and ns.bbaron.sk

dig sonic.sk @
sonic.sk.		3596	IN	A
dig sonic.sk @
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 40959
dig sonic.sk @ +trace
sonic.sk.		3600	IN	A
What else can I do ? How can I get the other dns servers to resolve my domain ??