This Microsoft outage being the last drop in the bucket, I’m looking to get my email/calendar/contacts somewhere under my control.

As I already self-host a number of things (e.g. my Linux ISO collection), and have services exposed to the internet, it would make sense to run it at home.

After all, it’s not heavy lifting. It’s not hosting 500+ mailboxes for 100+ people. It’s just little old me, with a handful of domains, catch-all receiving and a few dedicated sending addresses.

However email is a bit more mission critical than my smarthome control or self hosted LLMs. Downtime could be critically bad, and I still don’t trust my home setup to be truly 99.999999% available.

I don’t mind paying for a service but if I do I’d prefer something European, given I’m based in the UK (and otherwise am an EU citizen).

I’m really curious how y’all solve it. I guess I’m interested in some kind of hybrid solution where there’s my own server and a hosted service, latter which acts as a backup solution, but still fully synced, so if my internet or power goes out (or my server goes down), I can still get mail sent and delivered.

So I’m not only just interested in the stack you run for email but the entire infrastructure, especially if you’ve solved this sort of off-site fallback service.

  • dihutenosa@piefed.socialEnglish
    5·
    6 hours ago

    I self-host it with https://gitlab.com/simple-nixos-mailserver/nixos-mailserver.

    • I had to set it up with all these SPF and DKIM and DMARC stuff. Wasn’t too hard, just follow the guide. Test with GMail - the message details view says exactly what you have, what you haven’t, and what’s wrong.
    • Every now and then I have to jump through some hoops to get my IP allowlisted in some weird provider or antispam system.

    Email is a very old protocol, it originates from the time when computers were connected only occasionally. It is very much possible to come an agreement to power up the antennas at something o’clock every day to exchange emails, and the rest of the time they just sit in the queue.

    Practically speaking, if your home lab is down for something like 12h, it should not impact email delivery much at all - the sending servers would just keep retrying. Usually for 48h. From https://www.rfc-editor.org/rfc/rfc5321#section-4.5.4.1

    mail that cannot be transmitted immediately MUST be queued and periodically retried by the sender.

    The sender MUST delay retrying a particular destination after one attempt has failed.

    Retries continue until the message is transmitted or the sender gives up; the give-up time generally needs to be at least 4-5 days.

    Microsoft documents this: https://learn.microsoft.com/en-us/defender-office-365/mail-flow-about#mail-flow-delivery-faq

    Deferred messages remain in our queues for one day.

    I guess technically they’re RFC-compliant, but 1 day is not as much as I’d like…

      • dihutenosa@piefed.socialEnglish
        3·
        4 hours ago

        No idea. I keep hearing the term, “IP reputation”, but I don’t know any official registry where I could look up mine.

        • I can deliver to GMail, because I set up SPF, DKIM, DMARC, and that special GMail-only TXT record in DNS: "google-site-verification=<base64-or-what>"
        • I can deliver to Outlook, because I registered by IP in https://check.spamhaus.org/
        • Every now and then, I encounter a new, weird and wonderful kind of spam protection, and I have to figure out how to get my IP listed in the “known legit email servers”

        All told, I can deliver email, AFAICT. If it lands in spam, well, tough luck - email from large providers also does.