I have a question regarding email relay and mailing lists.
I was quite frustrated about my email server being ignored/blocked/categorized as spam. Despite correct SPF, DKIM, DMARC configuration and a score of 10/10 at mail-tester.com and high deliverability at all major email providers I have constant problems delivering to outlook.com and hotmail.com addresses. I know this is a widely discussed problem…
However, I now use a mail relay at mailjet.de. Everything is fine and thanks to this forum configuration was easy.
One problem remains: I use a UCS mail list for a defined number of users who have email addresses with domains not owned by me. Example:
UCS Maillist: email@example.com
UCS User : Email address
Me : firstname.lastname@example.org
UserA : Alfons@gmx.de
UserB : Bertold@gmail.com
UserC : Claudia@hotmail.com
Sending into the mail list email@example.com is restriceted to only members of the list. I have registered access to the mailjet mailrelay for *.mydomain.de, so firstname.lastname@example.org and email@example.com are allowed to use the mail relay.
In my understanding this is strange because sending would be:
What am I missing here? Can anyone help?