> However, two useful details have been exchanged that at least > clarify some possibilities: > > 1. It appears my IPv6 address for my new server instance has been > swept up into a spamhaus PBL entry. This wasn't the case during > initial setup and prior rounds of triage, but it'll certainly cause > issues now. > > 2. It appears the provider I'm attempting to use, Hostinger, has > made it onto sufficient other hidden black lists that the address > ranges are problematic. > > So, the issues are not configuration, they're collateral damage, > and there's diddly squat I'll be able to do about the issue aside > from "move somewhere more reputable". > > Unfortunately, good luck finding "somewhere more reputable". Long term, we have plenty of IPv6 addresses. So in theory you can get your own IPv6 prefix (or together with some friends) have it routed and use that. Short term, why not make a mail routing exception for Gmail? Just accept that you can only reach Gmail over IPv4. Or use a mail provider and route only mail with a gmail destination to the mail provider.
