Mails sent from Wordpress with the PHP mailer are sent from my_ssh_identity@opal15.opalstack.com
They often end up in junk mail and from checking the headers in the incoming mails this is probably due to missing SPF and DMARC. Problem is that since they are not sent from any of the email addresse I have defined myself I don't know where I could define the necessary DNS records.
Setting SPF and DMARC when sending mail from Wordpress with PHP mailer
You will need to specify a FROM address, which may include using a SMTP plugin to set the sender address as a real mailbox/email for outgoing messages. Then you can setup the DNS records for the email domain.
Yes, thanks. That works