IP reputation is a gamble, and there is no recourse. If you're lucky, awesome. But if you're unlucky and switching host isn't an option, you pretty much have to involve a large third party to act your behalf - there is zero appetite in the industry for interacting with individuals.

The best solution I've been able to find is to self-host /almost/ everything, but route outgoing mail through Amazon SES.

The pricing for vanity email volumes is negligible (a few cents a year), and they have people whose full time job is wrangling IP reputation / Office 365 / etc.

This setup has survived several ISP/hosting switches; at times when I am lucky with IP reputation I route only mail going to Office 365 recipients via SES and deliver the rest directly; at times when I am less lucky, everything goes via SES.

  SMARTHOST_FOR_MS = email-smtp.us-east-2.amazonaws.com::587
  smarthost:
    debug_print = "R: smarthost for $local_part@$domain"
    driver = manualroute
    domains = ! +local_domains
    transport = remote_smtp_smarthost
    route_list = hotmail.com SMARTHOST_FOR_MS byname ; \
                 live.com SMARTHOST_FOR_MS byname ; \
                 outlook.com SMARTHOST_FOR_MS byname ; \
                 msn.com SMARTHOST_FOR_MS byname ; \
                 live.co.uk SMARTHOST_FOR_MS byname ; \
                 hotmail.co.uk SMARTHOST_FOR_MS byname ; \
                 * DCsmarthost byname
    host_find_failed = defer
    same_domain_copy_routing = yes
    no_more

O365 and gmail should be honorably mentioned as places that will deliver both inbound and outbound to/from an IPv6-only MX.

A lot other servers will not play ball here. Your self-hosted mail server, if it lacks IPv4, will not get inbound from mailgun, mailjet, github; neither will it be able to send outbound to cisco/iphmx, and about 90% of small servers from what I see in my logs.

> i think the myth of "you can't self-host email" persists because while it can evidently be done, basically all of the software involved is ancient, baroque, inconsistently documented, requires a PhD in Bullshit to correctly configure, and is almost actively hostile to observation. but this is _annoying_, very different from _impossible_, and fortunately mostly solvable by delegating the annoying bits to an expert using something like NixOS to make it reliably work

Why are they calling this a “myth” when they readily admit that even when you are an expert who has been doing it for years, there’s still problems sending to the biggest providers in the world?

There is zero practical difference between “you need to be an expert and you will still fail to get something fundamental working” and “you can’t self-host email”.

> Microsoft 365 however apparently will hate your email no matter what. you learn to live with it

Or you don’t self-host but use a major email provider and don’t have the problem.

> there exist several pieces of folk wisdom:

> - "you cannot run your own mail server in 2025, this is too hard and time consuming" (completely false, i've done this since ~2010 with minimal ongoing maintenance)

This seems completely true according to what they themselves write. It is too hard and time consuming.

> I think the combo of "roll the IP gacha a few times" + "let it sit for 8 months while the VM idles" probably did me a lot of good here

Is letting it sit for eight months not “time consuming”?

> until I cleaned up my IP reputation (which has been awful for almost a decade) Gmail refused to deliver to anything but spam

This is not in any way acceptable to the average person, and it does not meet what most people would describe as “I can self-host email”. “I can self-host email but Gmail sends me to spam” is functionally equivalent to “I cannot self-host email”.

I am in favour of the middle ground. Rather than expending effort self hosting email, which while plausible is unequivocally a heavy lift for most, make use of smaller providers such as Fastmail or Protonmail. Just please stop consolidating the internet.