Hello everyone,
I just installed a Mailcow server on a server with a clean IP that is not on any blacklist. I have configured everything for the domain: DNS records, DKIM, SPF, but when I send emails to Gmail, they are considered spam. However, everything seems fine when I check the email header, everything looks good :

When I analyze the email header with MXToolbox, I get the following: :

However, when I test the DKIM key using a tool, the key is valid.
Do you have any idea where the problem might come from?
I have seen online that it could be related to the webmail adding a header, which is then seen negatively by mail servers. I’m not sure if the issue could come from that.
Thanks in advance