Hello, i switched the server and have now an IPv4 and and IPv6 Address for Shared-Hosting. Before i only have and used 1xIPv4 for all sites. On old Server i have no problems with Mail and Customerswebsites. Now i have a problem which i think came from using IPv6 too. gmail and freenet refuse mails from my sites. I searched since yesterday but cant figure out the correct setting. Now i am a bit confused and need help and clarity. Lets assume this facts: servername = server1 domain for mailing on server1 = mydomain.com customer 1 site = csite1.com customer 2 site = csite2.com Server and both IPs are at RZ-Server-Hoster, DNS is setup on other Domainprovider These are the settings on RZ-Server-Hoster IPv4 -> Reverse -> server1.mydomain.com IPv6 -> Reverse -> server1.mydomain.com These are the settings in DNS for mydomain.com and all other e.g. with there csite1.com instead of mydomain.com A Rec server1.mydomain.com -> IPv4 A Rec *.mydomain.com -> IPv4 AAAA Rec mydomain.com -> IPv6 MX Rec - Hostname = mydomain.com - Mailserver = mail.mydomain.com TXT - mydomain.com = v=spf1 mx -all These are the settings on server1 # hostname -> server1 # hostname -f -> server1.mydomain.com /etc/mailname -> server1.mydomain.com Checks from other Host at mydomain.com lookup IPv4 -> server1.mydomain.com lookup IPv6 -> server1.mydomain.com lookup IPv4 and IPv6 server1.mydomain.com -> IPv4 and IPv6 = ok lookup server1.mydomain.com -> IPv6 and IPv4 lookup mydomain -> IPv6 and IPv4 Checks from other Host at csite1.com lookup csite1.com -> IPv4 and IPv6 (same as for mydomain.com) so reverse lookup at IPv4 and IPv6 point to server1.mydomain.com On question in my mind is, have i set the DNS Recs for AAAA to fqdn or only to domain? So server1.mydomain.com and server1.csite1.com ... Should i also add an AAAA for *.mydomain.com as i setup for A Rec? To solve that i could switch to only use IPv4, but i think it should work with IPv6 too. So i need your help - thx.