On 15 Apr 2022, at 12:02, Al Iverson via mailop wrote: > On Fri, Apr 15, 2022 at 10:36 AM Grant Taylor via mailop > <mailop@mailop.org> wrote: >> >> On 4/15/22 8:24 AM, Al Iverson via mailop wrote: >>> Don't send to Gmail over IPv6. >> >> Drive by comment. >> >> It is possible to send to Google via IPv6. My personal / small / >> bespoke server sends to my Google hosted work address all the time over >> IPv6. > > You're not wrong. Depends on email volume level and server config. > They're just so sensitive to reputation for IPv6 sends, though. Don't > even try without SPF and DKIM, and even then, get ready for some > possible pain.
For well managed mail servers, supporting well managed mailing lists I see no practical difference between address families. I have visibility over a few boxes sending a few hundred thousand messages per day. They are all dual stack and provisioned on a cloud provider (gasp!). The two deliverability issues they've had in the last two years have been related to sending to Microsoft, over IPv4. I also see similar boxes, used mostly for one-to-one and small scale mailing lists in the same scenario, with the same results. Of course, this is a small number of samples and perhaps even anecdotal, but these kinds of absolute pieces of advice are perhaps not for everyone. Someone once said that IPv6 was an opportunity to introduce a good set of requirements into the email ecosystem (forgot who/where, and I'm paraphrasing). With the potential to send each individual email message over the lifetime of a mailing list from a unique IPv6 address, I think this is a good justification for this. Best regards -lem _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
