I wonder how realistic these days is it to run an IPv6-only e-mail server.

Anybody any thoughts? Well I doubt any of the larger mail services are without IPv6, but there's probably a lot of corporate internal mail servers that are.


I'm not an expert so someone please correct me if I'm out of turn. My understanding with IPv6 is that ISP support is not quite ubiquitous so depending on your relay/mail path emails may black hole.

In short I'd say it's probably too early, but as I said above I could be completely mistaken.

@rysiek if I correctly understand the yunohost email configurations, google drops mail coming from ipv6

@ilja @rysiek There are IPv6 only blacklists (I've complained on masto before about the bad interaction of OVH and spamhaus), but google does not block all ipv6 mail. A quick check of the logs suggests it's about 50/50 from one mailing list server to gmail. It could also be the case the less people have IPv6 reverse DNS set up, which would cause not just gmail but most smtp servers to block.

@rysiek only ~20% of people would have access to ipv6 (without vpn) so what kind of point are you trying to make with an ipv6-only server?

@rysiek The problem is that every time I have been considering doing IPV6 only stuff, a bit of FOMO comes creeping, as I worry that someone who happens to run an ipv4 only server wants to send me an important email.

@rysiek I came much closer to go #ipv6 only with a few months ago, but ultimately decided against me as I discovered that a few of the bigger players in the fediverse did not have IPV6 DNS entries.

Of course, that does not mean they have no connection at all and is unable to reach an IPv6-only system, but I took it as a bad sign. Maybe in a very far future, until the ipv4 won't be enought...
But there are some problems with the IPv6 ><

I mean.... You've got Gmail covered. That's what, 80% of email users? Great start.


It’s not, if you want to actually receive any emails. What I see in my Postfix log is that while Google and Microsoft MTAs run on IPv6, most of the smaller entities don’t even bother.

@rysiek I wouldn't risk it unless circumstances gave me no other option.

@rysiek Looking at the logs from the last month on my personal mail server, there are incoming connections from 135 unique IPv6 addresses and 2068 unique IPv4 addresses. Of course, most incoming mail is spam, so those number might not mean much.

@jec in a way that makes such an e-mail server actually useful, in practical sense, as an e-mail server.

@rysiek depends if your contacts are at ipv6 servers or not, i guess?
@rysiek You mean able to communicate with others? I guess it depends on how much you interact with non-mainstream services. I think there still are probably a lot of servers out there that don't support IPv6 at all.

Me for example, I wouldn't even be able to if I wanted - my ISP only gives me 1 static IP with the plan I'm able to pay.

@rysiek @meena not particularly. Mine is IPv4/IPv6. The majority of my traffic goes via IPv6 but any small email provider tends to go IPv4 only.

@rysiek I have a dual stack server. I send and receive mails to/from Gmail via ipv6.
But it looks like most SMTP servers work only with ipv4.

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