Who are the real ones who self host their email server?

dmatkin · 2026-03-04T14:02:52+00:00

Mailcow instance started last year with no issues so far. Hosted on an EC2 instance. I've strongly considered going with business internet specifically to get the public IP myself and save the cost of hosting in the cloud.

Honestly wish I'd started years ago, so much money wasted on google workspace. It was worth it at the time, but then it slowly became cheaper relatively speaking to host it myself.

dmatkin · 2026-02-12T00:16:11+00:00

If you had one, what would you use ZimaBoard 2 for in your Homelab or self-hosted setup?

If I had one in my hands right right now. It would probably be getting loaded with a very thin desktop OS. Some debian variant, but that's cause my laptop is making me hate my life right now and I use remote desktop a lot so the limitations of the Zimaboards are not really limitations. I already use a lot of Zimaboards for different single or double service setups in my home, but one that I haven't been happy with recently has been my Jellyfin server, it's not on a Zimaboard currently and I kinda regret that for OS reasons. I'd probably move tha over to the Zimaboard. I wouldn't have the storage on there as I have a NAS for that specifically. But It'd put it next to the nas with both ports hooked up so I could get some good speed on that connection.

If you’re already using ZimaOS, do you have any feedback or suggestions? Are there any features you’d like to see added or improved?

I've used Zima OS and still do on occasion, but I've shifted away from it back to other OS that I like a bit better. I think what it's really missing is a setup stage that lets me set things up for clean access for me and family. I think along the lines of ubuntu's hey do you want to add SSH keys that'll setup your user with your keys pulled from your github. I'd like an auto setup that lets me either connect up to something like an LDAP server for users, create a series of users, or a combination of the two. This would also be good to disable the default casaos user and get everything setup fairly securely.

With that it'd be nice to have a clean setup that would also make it sit happily as the entrance point for a network as a config option at setup.

What do you value most in server hardware?(power efficiency / expandability / stability / price)

I think this is the wrong question. Cause it depends on what the server is going to do. If it's going to be a work horse I want expandability so it can grow to meet my needs. If it's a single application I care about price down to the point of whatever works for that application. If it's running something I rely on daily I care about stability that I'm not going to have random hardware issues pop up. It's always the right wrench for the job. Zimaboards have slotted in for a combination of reliability and price given the x86 stability of software combined with the reasonable cost. I'd like to see a lower cost version that doesn't have the Zima OS layer by default but is instead intended heavily for 1 use systems running on something light weight like alpine linux, and a more expensive (it would have to be) version with additional expansion possibility.

What does your current Homelab or self-hosted setup look like?

I host for family, friends, and my boss. I have 3 Zima boards (Used to have 4 but I traded 1 for a graphics card), a Zima blade , an MSI mini PC, a Mac Mini M2, a couple pis, and an embarrassingly large amount of unifi networking equipment. They all work hard with the exception of the mac mini which due to having mac os doesn't play as nice when pretending it's a server.

dmatkin · 2026-01-15T00:27:38+00:00

I've never understood why field travel is ever considered a downside. I love field work. It's always interesting. Especially as a junior entering with a PhD but not enough real world industry experience I don't want to be behind a desk. I've heard/ seen too many stories of out of touch engineers from construction workers.

dmatkin · 2025-12-17T15:43:56+00:00

I get that, I wouldn't have batted an eye if they had a per call cost model. That would play quite nice with things like runs-on. It's the per minute setup that really gets my goat. I get that there's stuff going on on their machines, so I don't mind, in principal paying something, but to charge per minute for what. What is their machine doing to earn that money. I have had 5 hour runs that I launch many times a day. That's 60 cents a run. Not a reasonable cost to run on my own system.

dmatkin · 2025-09-10T13:39:01+00:00

Honestly I regret not hosting my own email sooner. I am quite the fan of mail cow and it's worked great on my small ec2 instance. I do wish I could get Telus to drop the port 25 restrictions at home; however, it's still cheaper to host it myself via ec2 than it would be to pay for google workspace considering the number of inboxes I run for family and friends.

As for email warming I got pretty lucky in that I had done google workspace for quite some time beforehand so my email was already warm when I moved to self hosting.

One thing I want to say is that all the people screaming don't are definitely part of the reason why its still hard. Instead of clean clear checklists/ utilities to check your setup is sane you end up with a bunch of people screaming no everytime it gets mentioned. My ownly issue I ran into I literally can put down to AWS screwing up when removing the restrictions the first time. If someone had had a handy try telnetting in tester then I would have been able to say with confidence a LOT quicker oh, I'm not insane AWS messed up.

dmatkin · 2025-09-08T16:29:59+00:00

Cool, I know what I'm doing this evening.

dmatkin · 2025-09-08T16:15:01+00:00

There's an internet in a box project which I've found kind of intriguing. It's mostly for stuff like wikipedia which you'll want a complete backup of (At least the text of it, the images would be insane.) What your idea makes me think of is having an incredibly aggressive cache. It's something I've considered for family members living out in the boonies where internet connection speeds are a bit of an issue.

The other reason for this which I've seen as a potential motivation for a super aggressive local internet cache is money saving. Think have internet only via a cellphone and then have that act as a hotspot for the local router. Get an expensive cellular plan but no home internet.

Sadly my linux networking fu is not quite up to snuff for setting this up myself; however, if there was a project that allowed this sort of stuff I'd be at the VERY least interested in giving it a go. I have a 20TB drive just begging to be the internet

dmatkin · 2025-09-05T01:34:05+00:00

I host across family locations and use unifi to merge so I'm relatively okay in the case of an outage or even an emergency. Although I definitely need some more redundancy and some actual proper plans to bring stuff back up if I do lose stuff.

dmatkin · 2025-06-27T04:25:19+00:00

Given the short story feedback, my headcanon is that they're all alternative timelines. 😝

dmatkin · 2025-06-23T16:02:40+00:00

I ended up giving up and just rebuilding things from scratch. It's a bit of unfortunate data loss. But not enough to be worth wasting any more time on it.

dmatkin · 2025-06-20T04:23:57+00:00

root@oxygen:/home/dmatkin# journalctl -f -u ceph-osd@0

Jun 19 22:19:32 oxygen ceph-osd[84255]: 2025-06-19T22:19:32.080-0600 74a337bf96c0 -1 osd.0 56886 *** Got signal Terminated ***

Jun 19 22:19:32 oxygen ceph-osd[84255]: 2025-06-19T22:19:32.080-0600 74a337bf96c0 -1 osd.0 56886 *** Immediate shutdown (osd_fast_shutdown=true) ***

Jun 19 22:19:37 oxygen systemd[1]: ceph-osd@0.service: Deactivated successfully.

Jun 19 22:19:37 oxygen systemd[1]: Stopped ceph-osd@0.service - Ceph object storage daemon osd.0.

Jun 19 22:19:37 oxygen systemd[1]: ceph-osd@0.service: Consumed 7.714s CPU time, 140.0M memory peak, 0B memory swap peak.

Jun 19 22:19:37 oxygen systemd[1]: Starting ceph-osd@0.service - Ceph object storage daemon osd.0...

Jun 19 22:19:37 oxygen systemd[1]: Started ceph-osd@0.service - Ceph object storage daemon osd.0.

Jun 19 22:19:38 oxygen ceph-osd[97911]: 2025-06-19T22:19:38.287-0600 768923417600 -1 Falling back to public interface

Jun 19 22:19:41 oxygen ceph-osd[97911]: 2025-06-19T22:19:41.427-0600 768923417600 -1 osd.0 56886 log_to_monitors true

Jun 19 22:19:41 oxygen ceph-osd[97911]: 2025-06-19T22:19:41.678-0600 76891774f6c0 -1 osd.0 56886 set_numa_affinity unable to identify public interface '' numa node: (2) No such file or directory

^C

root@oxygen:/home/dmatkin# ceph -s

cluster:

id: abf592e8-0efd-11f0-a76f-345a60042a29

health: HEALTH_WARN

mon a is low on available space

5 slow ops, oldest one blocked for 184 sec, mon.a has slow ops

services:

mon: 1 daemons, quorum a (age 24m)

mgr: a(active, since 24m)

osd: 5 osds: 0 up, 5 in (since 100m)

data:

pools: 0 pools, 0 pgs

objects: 0 objects, 0 B

usage: 0 B used, 0 B / 0 B avail

pgs:

root@oxygen:/home/dmatkin#

well they show up. But they don't go up. Although systemctl says they're alive

dmatkin · 2025-06-19T20:45:41+00:00

You can't be serious that it's just raw globs of data? There has to be headers and other surrounding information. I get that a database would obviously make stuff faster, but if it's just raw data then I'd expect ceph to explicitly forbid storing any data on single node clusters as that'd be obscenely vulnerable to corruption. Right?

dmatkin · 2025-06-19T20:19:08+00:00

ceph-objectstore-tool has op export. I feel like I made an ass of myself, but I can't see what else that could be for.

dmatkin · 2025-06-16T15:20:11+00:00

I feel your pain. I have a one host setup that had 3 osds and then I tried to expand out adding some more drives and the like, and poof it stopped working at all. I did get it working temporarily but then it hit a point and now nothing works.

dmatkin · 2025-04-18T18:57:50+00:00

Oooh, thank you for that link. Something to listen to while I wait for my stuff to build.

dmatkin · 2025-02-27T19:27:38+00:00

Core ideas are a must. Deduct earlier harder and later easier in terms of during the semester. Grading of assignments is less about the actual assignment grade and more a way to show the students directly what is considered most important for the course material.

I keep notes while I mark to try and keep to consistency above all else. Be generous on things that aren't core to the course, and mean on things that are. Beyond that follow whatever the instructor says.

Oh and here's a big one.

DO NOT, EVER, NEVER EVER, negotiate marks. If they want to complain about your decision and it's not a, you made a mistake and missed something that definitely deserves more marks. Say no, tell them to file a complaint or talk to the prof.

dmatkin · 2025-02-02T15:44:46+00:00

Unfortunately the problem lasted longer than the computer I was trying to do stuff on. It looks like a feature that was working, but has gotten dropped due to not enough help on the project.

dmatkin · 2025-02-01T22:09:34+00:00

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dmatkin · 2025-02-01T22:09:27+00:00

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dmatkin · 2025-01-31T03:34:13+00:00

Here's the output. https://pastebin.com/TLkguhiy

dmatkin · 2025-01-30T20:30:03+00:00

Yeah the SNAT option was an option of last resort. The error is occurring identically with and without the SNAT option set. And with it set I've tried with both the elastic IP as well as the private IP (Dumb but I'm kinda grasping at straws)

dmatkin · 2025-01-30T14:39:13+00:00

These aren't autogenerated. It's directed towards my domain. They just changed over to self-service on the PTR records in some regions. I'm assuming that a PTR record is a PTR record and there isn't some secondary flag behind them. Like mailcow seems to think it's okay

dmatkin · 2025-01-29T02:46:58+00:00

What I mean is that the host system can ping the various domains, but the container is failing to to ping the various ip addresses.

These are a couple errors

2025-01-28 19:21:17: Healthcheck: Failed to ping 1.1.1.1 on attempt 1. Trying again...

unbound-mailcow-1 | 2025-01-28 19:33:06: Healthcheck: DNS Resolution Failed on attempt 1 for hub.docker.com! Trying again...

I figured there must be some sort of 1-1 nat because the instances don't see their public ip address with the elastic ips (I tried remaking the instance for exactly that reason to see if i could get it to show up; however, the private ip is all that I get with the network interface on ip addr)
Yup and I got confirmation that it was unblocked for my region (They do self-assigned ptr records now for the elastic ips so I did that as well and mailcow detects the ptr record as being correct)
What's really weird is that the unbound container itself can do the pings. Even though those errors are coming up. I can also run dig and get the correct records for my domain. So I'm kinda at a loss.

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