MailServer with Cloudflare but main website is on another IP


I installed CyberPanel on a fresh ubuntu vps with it’s main purpose to be a mail server let’s say with IP

Then on the panel I created a website (as container for emails), and then an email adress.

I need all the DNS te be on Cloudflare and the main IP adress of the domain is pointing to another server because the website is on another server.

On cloudflare I configured the DNS as is for now :
A domain.tld TO // main website (other server)
A mail.fomain.tld TO // CyberPanel mail vps server
MX domain.tld TO mail.domain.tld
TXT default._domainkey.domain.tld TO "v=DKIM… (took it from the panel)
TXT _domainkey.domain.tld TO t=y; o=~;
TXT domain.tld TO v=spf1 a mx ip4: ~all.

With that I can send and receive emails BUT when I test the sending of an email with I get this:
-0.1 DKIM_INVALID DKIM or DK signature exists, but is not valid
-0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid
This rule is automatically applied if your email contains a DKIM signature but other positive rules will also be added if your DKIM signature is valid. See immediately below.
-0.001 HTML_MESSAGE HTML included in message
No worry, that’s expected if you send HTML emails
-1.274 RDNS_NONE Delivered to internal network by a host with no rDNS
This may indicate you do not have a rDNS configured for your hostname or the rDNS does not match your sending IP
0.001 SPF_HELO_PASS SPF: HELO matches SPF record
0.001 SPF_PASS SPF: sender matches SPF record
Great! Your SPF is valid

[SPF] Great! Your server is authorized to use contact@domain.tld
Your DKIM signature is not valid
Your message passed the DMARC test
Your reverse DNS does not match with your sending domain.
Your domain name domain.tld is assigned to a mail server.
Your hostname domain.tld is assigned to a server.
Your message could be improved
You’re not blacklisted
No broken links

What am I missing? Thank you