- Plesk for Linux
- Plesk for Windows
- Mails sent from Plesk are marked as spam by a remote mail server.
- SPF and DMARC are configured correctly as can be seen from mail header:
CONFIG_TEXT: Authentication-Results: mx.google.com;
spf=pass (google.com: domain of email@example.com designates 203.0.113.2 as permitted sender) firstname.lastname@example.org;
dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=example.com
3. There is no PTR record in Plesk > Domains > example.com > DNS Settings
Spam filter marks emails sent from domains without PTR record as spam.
Set up a proper PTR record for the domain, as explained in the article How to add PTR record for a domain in Plesk?