I can send fine, everything works; spf, dkim and dmarc. Mail is received at its destination with “clean” headers.
The loopback problem is with receiving. The message was not in a log, it was in a bounce back from an email I tried to send from another server to myself. Too tired/bleary eyed…
2:33 PM (2 hours ago)
This is the mail system at host mail.domain.website.
I’m sorry to have to inform you that your message could not
be delivered to one or more recipients. It’s attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
firstname.lastname@example.org: mail for domain.website loops back to myself"