sendmail error "Recipient not found"


I have installed FreeBSD 10.2. The default mail server is sendmail. I blocked a domain and have assigned it the static IP that i got from ISP. Below is the "drill" output.
Note- Domain and IP address are masked. The IP that i get from "drill" is the correct static ip.
$ drill
;; ->>HEADER<<- opcode: QUERY, rcode: NOERROR, id: 14856
;; flags: qr rd ra ; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; IN  A

;; ANSWER SECTION:  599  IN  A  zzz.zzz.zzz.zzz



;; Query time: 69 msec
;; WHEN: Fri May 27 12:47:03 2016
;; MSG SIZE  rcvd: 45
With no other changes, sendmail is working for users with in the localhost. But if I try to send mail from gmail or any other account I get a response of "550 Recipient not found". After searching in google. I added the below line in /etc/mail/ and then followed it with make, make install and then "service sendmail restart". All the steps are successful.
Still, I am getting the same error. If the "drill" output is correct, then I hope the question of DNS maintenance is out of scope. Or if DNS is the problem, i would like to know the entry as well whether it be should maintained in my server or in the domain registrar server where i have maintained the static ip also.

It should still try to deliver the mail even if MX records are missing but an A record exists for the domain. Verify that google actually tries to deliver the message by looking at the mail logs, /var/log/maillog is the one used by Sendmail. If there's nothing in the logs the problem is really the missing MX records which you should set up anyway, some mail handlers actually block domains that have only A records.

Thanks for the responses. Along with domain registration, my domain registrar had given free emails. Hence the MX record was pointing to their servers. Moreover, my bad not to recognize the full error message. One half of the message is "550 Recipient not found" but this message was followed by "from" which ofcourse is the mail server of the domain registrar. Updated the MX records and the mail is working fine now.