What to register in the DNS of the domain on the hosting, for the mail server that is in the office?

Question

Domain Name System

All the best!
The situation is as follows
Initially, the example.com site was located on a server in the office, the mailer was on the same server, then the task was set to move the site to an external host. I rented a VPS with the ISPmanager panel, the site was transferred, the mailer, as expected, fell off.
As a matter of fact, the question is, what should be specified in the settings of the dns zone so that the letters go?
At the moment I tried the following configuration:
domain: examole.com Office
IP address 2.2.2.2
VPS IP address: 1.1.1.1
example.com. 3600 A (Internet v4 address) 1.1.1.1
www.example.com. 3600 A (Internet v4 address) 1.1.1.1
ftp.example.com. 3600 A (Internet v4 address) 1.1.1.1
mail.example.com. 3600A (Internet address v4) 1.1.1.1
smtp.example.com. 3600 A (Internet v4 address) 1.1.1.1
pop.example.com. 3600 A (Internet v4 address) 1.1.1.1
server3.example.com. 3600 A (Internet v4 address) 2.2.2.2
example.com. 3600 MX (mail server) server3.example.com. priority = 10
example.com. 3600 NS (name server) ns1.sddd.ru.
example.com. 3600 SOA (initial zone record) root.example-server.ru.
example.com. 3600 TXT (text entry) v=spf1 ip4:1.1.1.1 a mx ~all I'm trying
to set up thunderbird, but it doesn't want to log in
Thanks!

Answer 1

how much mail per day? if up to 3000 per domain - transfer to pdd.yandex and don't suffer. everything goes everywhere, there are no blacklists and spam.

Answer 2

mail.example.com on 2.2.2.2 - so TB can even find the configuration automatically. And look at the log on the mailer - does the authorization request come from TB. The log can be made more detailed, maybe an error will appear there.