What steps should I take after my ISP has set a reverse DNS (PTR) record for my mailer?

Question

Domain Name System

Hello,
I have LAMP, Postfix and BIND on my local (single) computer. I finally asked my ISP to update the rDNS (PTR) record for my static IP with them. And then there were problems with the delivery of mail sent from my mail server. Now my IP normally resolves to something like:
mail.mysite.com
Everything seems to be working fine for me in terms of my servers. Nothing strange and no obvious problems, as it were, and no.
In nslookup, when I choose as the DNS server Google (8.8.8.8), it shows everything is fine when checking the reverse DNS. But my DNS server issues SERVFAIL. So what should I do, just wait some more time for DNS propagation (my ISP changed rDNS 6 hours ago) OR do I have to change my own DNS server settings (BIND9)?

Answer 1

In short, I set everything up like this:
Let's say my IP will be 46.249.xx.yy
In the named.conf.local file, I entered this about the reverse zone:

zone "xx.249.46.in-addr.arpa" {
type master;
file "/etc/bind/zones/db.46.249.xx";
};

In the file db.46.249.xx, which is in the "zones" directory, I did this:

;
; BIND reverse data file for local loopback interface
;
$TTL	604800
@	IN	SOA	ns1.xxxxxxxx.com. director.xxxxxxxx.com. (
            2		; Serial
       604800		; Refresh
        86400		; Retry
      2419200		; Expire
       604800 )	; Negative Cache TTL
;

@      IN      NS     ns1.
yy     IN     PTR     ns1.xxxxxxxxxx.com.
yy     IN     PTR     mail.xxxxxxxxx.com.

Now, when I restart BIND, there are no more errors in the debug.log log, and when I do:
nslookup 46.249.xx.yy I get 2 answers:
and
now when I check:
named-checkzone xxxxxxxxx.com /etc/bind/zones/db .46.249.xx
I get OK
PS In short, I just had a mess in the reverse zone file and all my business with the ISP and the mailer had a rather indirect relation to this.