Problem Sending email Need Help

Ok. so this is been a nightmare for me, it may be an ease thing for you, thats why im asking for help.
this is the scenario.
i have a customer that has his domain name, website, and email (microsoft365) with godaddy .
when i try to send an email from my email created with cyberpanel to customer email i get in my imbox this emial
Undelivered Mail Returned to Sender*



But when i send it from my email created in cyberpanel to a GMAIL account it goes true…
so i was thinking that maybe his email has a problem, so i send him an email from my Gmail account and he is able to receive it with no problem.
what can be causing this problem. this are the pictures of the email i get and i know alot of you probably are very familiar with this problem but im new to it so please help me out. and if you can help me please.
i already did an email test at test-mcguwzu5s@srv1.mail-tester.com
https://www.mail-tester.com/
and this are my results




mail.axiomteck,com using cloudflare?
how about other domain ?

Please show the DNS records and all details

few days ago i moved my domain name to namecheap because cloudflare is not allowing me to add my custom NS1 and NS2, so all i have in namecheap is ns1.mydomain.com ns2.mydomain.com

other domain is using godaddy. and im going to point his A record to the new website created with cyberpanel but only the A record im going to change it to the new server that is created with digital ocean droplet and cyberpanel

please do : Problem Sending email Need Help - #3 by shoaibkk

from where u want me to show the DNS records from Cyberpanel, from the Email i get back when i send email, or from email-tester

i try to send an email to HP to find a part, and im also getting Mail Delivery System
back that did not go true.

Digital ocean …

you need mail digital ocean staff to allow you sent email

Why is SMTP blocked? :: DigitalOcean Documentation