You can continue to use the old IPv4 subnet with a new server at Hetzner. With IPv6, it does not work unfortunately. Although I do not understand why I can keep all IPv4 (subnet and / or single), but not the IPv6 addresses. It’s annoying when you have to change […]
If you see host aspmx.l.google.com[2607:f8b0:400d:c02::1b] said: 550-5.7.1 [2607:5300:101::79e] Our system has detected that this message does 550-5.7.1 not meet IPv6 sending guidelines regarding PTR records and 550-5.7.1 authentication. Please review 550-5.7.1 https://support.google.com/mail/?p=i…tication_error for more 550 5.7.1 information. h1si3408978qew.71 – gsmtp (in reply to end of DATA command) the destination dropped […]
To send outgoing mail with postfix for certain domains only over IPv6 or IPv4, only a few changes are required. The domains are registered in accordance /etc/postfix/transport examplev4.de smtp-ipv4-only: examplev6.de smtp-ipv6-only: /etc/postfix/master.cf: smtp-ipv4-only unix – – n – – smtp -o inet_protocols=ipv4 smtp-ipv6-only unix – – n – – smtp -o inet_protocols=ipv6 /etc/postfix/main.cf: transport_maps = hash:/etc/postfix/transport: Execute postmap hash:/etc/postfix/transport and […]
There are various possibilities to deactivate IPv6 on linux-systems. You can modify entries under /proc, experiment with the kernel modules or god knows what all. I prefer to add just one entry to the grub-option. So i can easily reactivate IPv6 with one step. ipv6.disable=1 After a reboot, the IPv6 […]