IPv6 Deactivated for our Incoming Mail Servers

Naturally, we’ve set up new IPv6 addresses for our mailbox.org mail servers, in addition to classic IPv4 addresses. IPv6 is the latest Internet protocol that has become necessary due to the lack of available IPv4 addresses. Several months ago, the media spent some time reporting on this topic and many providers are currently in the process of introducing IPv6.

Unfortunately, we’ve become aware in recent weeks that increasing numbers of other providers are beginning to send their e-mails via IPv6 but, in very many cases, they have not yet mastered how to configure their mail servers. As a result, mail sent from these malfunctioning IPv6 mail servers has very often been rejected (quite rightly) by other mail servers as spam sent from mail servers that are quite obviously unsafe and not working properly. It’s quite clear that the fault lies with the incorrectly configured sending mail servers.

It is frustrating to see how many postmasters do not have their systems under control and are unaware of how important it is to configure their mail servers properly and, above all, maintain a clean domain name system for their mail servers.

But, there’s nothing you can do: When e-mails don’t arrive, recipients often accuse their mail provider, even if the latter can do nothing about it. And, of course, this ends up being twice as frustrating for us.

If you’ve experienced difficulties with e-mails not arriving over the past few weeks, this was probably due to this IPv6 problem.

This is why we’ve recently decided to temporarily deactivate the IPv6 addresses of our incoming mail servers in order to avoid these problems until other postmasters will have gotten a handle on their IPv6 systems in the coming months.

As a user, this makes no difference to you. All we’re trying to do here is tell you something about the technical background to our work. This change only involves the mail servers to which other providers deliver e-mails. The mail servers for POP3/IMAP and SMTP authentication that are used by our users are still accessible via IPv6.