Our _dmarc TXT record by default protects all subdomains, so an
adversary can't send mails on behalf of any subdomains (p=reject, p
stands for policy). We add a _dmarc.list TXT record with the same policy
to allow sending mails via list.pub.solar's postfix.
See https://dmarcly.com/blog/how-dmarc-works-with-subdomains-dmarc-sp-tag
for more context
The pub.solar website and www record now live on flora-6
mail.greenbaum.cloud -> mx2.greenbaum.cloud
Remove non-functional mail, imap and smtp records.
mx2.greenbaum.cloud is responsible for mails as per MX record
Namecheap likes to add the root dot to DNS records, let's follow its preference
Benjamin Bädorf
teutat3s