Why isn't the MX record propagating after pointing a domain to Yahoo Mail Server?

I took a look, unfortunately I couldn't find an MX record, the SOA record shows me that something was last changed to the dns records on March 23. When did you make your changes?

;kmtc.com.sa.                   IN      MX

;; AUTHORITY SECTION:
kmtc.com.sa.            900     IN      SOA     ns01.trademarkarea.com. postmaster.kmtc.com.sa. 2021032365 3660 1000 604800 84600

DNS doesn't propagate; the responses from authoritative servers are cached by the recursive servers. Currently your authoritative servers are responding with an empty set of MX records, so they are not configured correctly.

$ dig kmtc.com.sa. MX @ns01.trademarkarea.com

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 33020
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; QUESTION SECTION:
;kmtc.com.sa.                   IN      MX

I'm afraid you have to wait for the response from your DNS provider.

There is nothing to propagate. The DNS servers that are authoritative for your domain kmtc.com.sa do not have any MX record for your domain. This means you are configuring in the wrong place.

[mot@boo ~]$ whois kmtc.com.sa|grep -A 3 "Name Servers"
Name Servers:
ns01.trademarkarea.com
ns02.trademarkarea.com
ns03.trademarkarea.com
[mot@boo ~]$ host -t mx kmtc.com.sa ns01.trademarkarea.com
Using domain server:
Name: ns01.trademarkarea.com
Address: 209.217.79.189#53
Aliases: 

kmtc.com.sa has no MX record
[mot@boo ~]$ host -t mx kmtc.com.sa ns02.trademarkarea.com
Using domain server:
Name: ns02.trademarkarea.com
Address: 65.60.27.192#53
Aliases: 

kmtc.com.sa has no MX record
[mot@boo ~]$ host -t mx kmtc.com.sa ns03.trademarkarea.com
Using domain server:
Name: ns03.trademarkarea.com
Address: 198.20.101.138#53
Aliases: 

kmtc.com.sa has no MX record
mot@boo:~$ host -t NS kmtc.com.sa ns01.trademarkarea.com
Using domain server:
Name: ns01.trademarkarea.com
Address: 209.217.79.189#53
Aliases: 

kmtc.com.sa name server ns02.trademarkarea.com.
kmtc.com.sa name server ns01.trademarkarea.com.
kmtc.com.sa name server ns03.trademarkarea.com.
mot@boo:~$