So I’ve been running self-hosted email using Mailu for a couple of months (after migrating out of Google Workspace). Today it turned that although my server seems to be capable of sending and receiving emails, it also seems to be used by spammers. I’ve stumbled upon this accidentally by looking through logs. This seems to have been going on for all this time (first “unknown” access happened just a couple of hours after I’ve set everything up).

While browsing the logs there were just so many crazy things happening - the incoming connections were coming through some kind of proxy built-in to Mailu, so I couldn’t even figure out what was their source IP. I have no idea why they could send emails without authorization - the server was not a relay. Every spammy email also got maximum spam score - which is great - but not very useful since SMTP agent ignored it and proceeded to send it out. Debugging was difficult because every service was running in a different container and they were all hooked up in a way that involved (in addition to the already mentioned proxy) bridges, virtual ethernet interfaces and a jungle of iptables-based NAT that was actually nft under the hood. Nothing in this architecture was actually documented anywhere, no network diagrams or anything - everything has to be inferred from netfilter rulesets. For some reason “docker compose” left some configuration mess during the “down” step and I couldn’t “docker compose up” afterwards. This means that every change in configuration required a full OS reboot to be applied. Finally, the server kept retrying to send the spammy emails for hours so even after (hypothetically) fixing all the configuration issues, it would still be impossible to tell whether they really were fixed because the spammy emails that were submitted before the fix already got into the retry loop.

I have worked on obfuscation technologies and I’m honestly impressed by the state of email servers. I have temporarily moved back to Google Workspace but I’m still on the lookout for alternatives.

Do you know of any email server that could be described as simple? Ideally a single binary with sane defaults, similarly to what dnsmasq is for DNS+DHCP?

    • Shdwdrgn@mander.xyzEnglish
      131·
      1 year ago

      I agree that a static IP address is an absolute requirement for a mail server to send messages these days. You also need a host of checks in place like SPF, DKIM, and DMARC, along with a strong set of blocklists and spam filters. My own setup includes dual ISP connections from two different providers, and even with all that in place, Microsoft has always been a thorn. They will block me for no apparent reason, their own tools don’t even show any detected spam activity, and sometimes they don’t even block the same IP address (or provider) that my emails were sent from. Every other spam service on the planet behaves in a rational way, but of course Microsoft has made a point of locking in so many businesses to their own spam-ridden service that you simply can’t run a mail server any more without being able to talk to them.

      Overall, yeah it can be a pain to run your own mail server. I can’t imagine trying to use a pre-built mail server and expect it to run, there’s so much that you have to configure to each specific setup. It’s not like a web server where you load up a docker container and it just works.

      • witten@lemmy.worldEnglish
        4·
        1 year ago

        I’ve had similar experiences trying to send mail to Microsoft-hosted email addresses. My current “solution” is to send all outgoing mail directly from my VPS-hosted Mailu server… EXCEPT for Microsoft-destined mail. For those messages, they get transparently relayed from Postfix to a third-party email sending service that Microsoft apparently trusts.

        The upshot is I can still use my own Postfix daemon for all mail sent to sane (non-Microsoft) providers.

        • Chobbes@lemmy.worldEnglish
          2·
          1 year ago

          I’ve never heard of anybody relaying just the Microsoft e-mails, but that’s a really funny spiteful solution.

          Lately I’ve been able to send to outlook just fine (maybe it’s just dumb luck, who knows). I think I had troubles initially because they’re really picky about rDNS matching the MX exactly. I also signed up for SNDS just in case, but I don’t know if they factor that in…

          • Neo@lemmy.hacktheplanet.beEnglish
            1·
            1 year ago

            In my experience (self hosting mail since 2005) signing up for SNDS does factor in. Although last time I had trouble with delivery to MS, my hosting provider Linode’s support also helped out by contacting MS back channels on my behalf. The biggest problem I (rarely) have is when whole IP blocks end up on a ban list that MS seems to really trust. That said, fuck it, I will keep fighting the fight and self host my mail like a stubborn old git :p

            • Chobbes@lemmy.worldEnglish
              1·
              1 year ago

              Hell yeah :). I’ve heard people have had problems with Linode’s IP blocks with MS… I’m glad to hear that Linode was actually able to help you resolve the problem. The biggest problem seems to be that you just might not realize if your e-mails are being dropped. Not sure if MS will notify you via DMARC if your IP block has been blacklisted, from the sounds of things they probably don’t and just silently drop things, so I guess you have to monitor the blacklists yourself?

          • witten@lemmy.worldEnglish
            1·
            1 year ago

            Ooh, lucky you! Maybe it was both the rDNS and the SNDS. Part of the problem IMO is it’s such a black box…

            • Chobbes@lemmy.worldEnglish
              2·
              1 year ago

              Definitely. It’d be nice if there was more reporting when a provider drops your messages.

  • slander@lemm.eeEnglish
    8·
    1 year ago

    unless you realllllly enjoy self hosting your email, IMO it’s just not worth it anymore with the state of things. I use Fastmail and could not be happier.

    • RegalPotoo@lemmy.worldEnglish
      2·
      1 year ago

      I’d be super cautious about relying on any company that even offers a “lifetime” plan.

      Offers like that are tools to raise cash - take money now for a service that you will provide people in the future. They tend to get used in one of two situations:

      • We need to raise money for investment in upgrades, so take the equivalent of ~2-3 years subscription from people up front, and count on the investment bringing in enough new customers paying regular rates that you can cover the cost of having the lifetime customers out of revenue
      • We need cash now or we aren’t going to be able to pay salaries, and it won’t matter that we’ve screwed our customers if we are bankrupt

      Even in the best case, it’d be much simpler to raise cash through usual investment mechanisms, so you do have to wonder how viable their business strategy is if they can’t get money that way

    • chrizl@feddit.chEnglish
      1·
      1 year ago

      Do you maybe have a link for the lifetime plan? Because I cant find it.

  • robert@lemm.eeEnglish
    2·
    1 year ago

    I vote for maddy, but one important note for my setup: my family uses always-on VPN, so i only open port 25 for the world. Imap can be accessed only from vpn. In such case server can’t be used as relay from internet. Maybe try that way?

    • Socket462@feddit.itEnglish
      2·
      1 year ago

      I am not saying your server is not secure, but just fencing off IMAP from the web is not enough to limit spammers from relaying mail through your server. They usually exploit a misconfigured SMTP server, which does run on port 25 (plain or start TLS mode)

      • robert@lemm.eeEnglish
        1·
        1 year ago

        That’s right, i’ve mixed two topics. Thanks for pointing that out

  • originalucifer@moist.catsweat.com
    31·
    1 year ago

    im an old school email admin. i gave up on my personal exchange box for protonmail years ago… multiple domains, lots of dns nonsense on my part. zero problems.

    i highly recommend them.

  • markstos@lemmy.worldEnglish
    2·
    7 months ago

    I hosted email professionally for over a decade… and I can’t recommend getting back into the business. At that time we were using Qmail, although I also have experience managing Exim and Postfix. About 90% of incoming email remains spam.

    For outgoing email for things like server cron mail, a stub service like msmtpdcan be used to receive local mail and forward it to to a local service.

    To receive and host email, Fastmail is good.

  • beirdobaggins@lemmy.worldEnglish
    2·
    1 year ago

    Moved from a junky setup where I was forwarding my domain mail to gmail. And sending mail through gmail using the smtp server provided by my web host.

    I was having too many issues.

    I switched to fastmail. It is quite good. And you can get some free basic web hosting included with your paid service.

    • ssdfsdf3488sd@lemmy.worldEnglish
      2·
      1 year ago

      This is what I did too, after self hosting and self hosting anonaddy for a while. I really like how it integrates into bitwarden to give me most of what I liked about anonaddy as an included thing. I also did it ofr the same reason. Too many Eh holes out there that just want to bang on the mail server all day.

      I ended up on purelymail.com for my machine sending email (it’s dirt cheap I think I will be under their minmimum and it will cost something like 10 dollars a year for unlimited unique email addresses for my services)…

    • Oliver Lowe@lemmy.sdf.orgEnglish
      2·
      1 year ago

      This was the provider I went with after self-hosting my mail for 7+ years on an OpenBSD VPS. I feel like Migadu is an honest and good-value service.

    • lemmyvore@feddit.nlEnglish
      2·
      1 year ago

      Great configuration, very flexible and fill of features. They make it easy to get all the DNS records you need to add to your domains and they have a diagnostic tool that checks that everything is set correctly. They even include wildcard aliases (which I’m not sure if it’s mentioned in their public pages).

      Should also note that they don’t limit accounts, domains, aliases or any features, just overall mails and storage space. The only additional limitation on the lite account is inability to set account quotas.

  • Cosmos7349@lemmy.worldEnglish
    1·
    1 year ago

    I use fastmail, and I enjoy it a lot. Their masked email is very nice as well, and integrates with bitwarden. So quite convenient to use my personal domain for stuff where my identity matters, and use masked @fastmail addresses for more disposable stuff.

    The only thing that ticks me a tiny bit is that their mobile app doesn’t have offline mode; but you can use imap client or w/e, so it’s not too much of an issue.

    Also hear good things about protonmail; I would consider it if I didn’t already use/trust fastmail.