SPF, DKIM, DMARC, MX, and CAA configuration
SPF
25
/25
DMARC
22
/30
DKIM
0
/20
MX
10
/10
CAA
v=spf1 include:mailout.uni-due.de -all
v=DMARC1; p=quarantine; aspf=s
mx-serv4.uni-due.de.
mx-serv5.uni-due.de.
mx-serv3.uni-due.de.