Email Authentication
mail.zcu.cz
SPF
passDeclares which servers may send mail for this domain.
v=spf1 mx ip4:147.228.0.0/16 ip6:2001:718:1801::/48 -all
DKIM
noneCryptographic signature on outbound mail (selector: none).
No record published.
DMARC
noneTells receivers what to do with mail that fails SPF/DKIM.
No record published.
Mail Servers (MX)
10 fred.zcu.cz