Olivier MJ Crepin-Leblond:
> Use the notation with the square brackets:
>
> [::1]:10028
>
> They are used to differentiate the colon used for separaring the port,
> as opposed to a colon which is part of the IPv6 address.
The form [::1]:10028 is safe everywhere Postfix allows host:port.
Postfix supports the form ::1:10028 here, too (see example in the
master(5) manpage), because the port is required, so that Postfix
can parse this string from right-to-left.
When the port is optional (as with the SMTP client destination
syntax) then the [] is required with IPv6 addresses.
Wietse
