Email forwarding to Gmail is not working

Hello,

on my cwp server both sending and receiving emails are working.
The problem is the emails are not forwarding to gmail, i have also tried hotmail.com and it is forwarding to hotmail.com:

sender: admin@domain.com (my own domain)
alias adress: admin@domain.com
Also have admin@domain.com account and checked with roundcube

Forwarding to:
admin@domain.com => works
test@hotmail.com => works
test@gmail.com => does not work, also checked the email adress and spam folders twice

As a workaround is there a options on roundcube to forwarding all incoming emails?

Google enacted strict requirements to send email to their servers.

You need to have a valid rDNS, SPF, DMARC and DKIM now, or it will bounce.

Any correctly configured mail server should have these already setup.

MTA-STS is optional, but is highly suggested. Especially by M$

The problem is not sending the email.
I am able to send to gmail by roundcube on cwp.

The problem is redirecting to gmail is not working instead hotmail/outlook is working

Roundcube isn't MTA (Mail Transfer Agent). It doesn't do anything to transfer emails between servers. When you use Roundcube to manage emails it connects to Dovecot to retrieve emails stored in the mailbox and to Postfix (MTA) to send emails.

CWP logs all mail events (authentication, sending, receiving, forwarding) into mail logs. Therefore if you want to to investigate why gmail doesn't accept forwarded emails from your server then review the mail logs (/var/log/maillog) to investigate the problem.

Welcome back, cyberspace!