Issue emails from webmail goes straight to SPAM

[digitar.be]

Hi,
We have an issue with our fresh server, all the emails sent from any of our client's domain webmail go straight to the SPAM/Junk Folder.
Here are the mail settings in the attached files
Can anyone point us in the right direction to solve this problem?
Thanks

 

[PAM Baduijn]

Did you check the ip reputation?
On Vultr DO etc. the ip addresses are recycled.

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dnschecker.org

 

[weltonw]

See: Question - How to prevent mail from being marked as spam with Google and other mail services?

 

[Bitpalast]

In case that only mails sent from webmail are going to spam, the reason is that the "myhostname" variable is not set in /etc/postfix/main.cf. Postfix is then sending the mail with 127.0.0.1 as sender IP which does not match the server's public ip. This leads to the spam classification. Simply add a line "myhostname = ..." with ... = your hostname, then restart postfix (# service postfix restart).