[stonewall]

1. Yes, most people will tell you not to host your own email, because its too complicated/difficult to get your mail delivered reliably.

A lot of this is FUD. Yes, email is a bit more difficult to get right than say, hosting a web app behind Nginx. It's an old protocol, with many "features" bolted on years later to combat spam.

I'm not sure how email is easier to "hack," unless there is a zero day in Postfix or something. Back in the day, lots of script kiddies would find poorly configured mail servers that were happy to act as an open relay...maybe the stigma persists?

To deliver mail reliably, you need 4 things (in my experience):

- A static, public IP address with a good reputation (ie, not on any spam blacklists)

- A reverse DNS record that resolves back to your mail server's IP

- A domain SPF record that says that your mail server is allowed to deliver mail

- DKIM records and proper signing of outgoing messages (DMARC records help too)

2. I have a residential cable internet connection, but pay extra for static IPs. You can probably get by with a dynamic IP and some kind of dynamic DNS service, as long as you don't want to send email. You could still receive email locally if your MX recorded pointed to some kind of dynamic DNS record.

Note that some ISPs explicitly block outbound traffic on port 25 due to spammers. You might need to check with yours.

3. The only things I expose to the internet are Postfix (to send/receive emails), XMPP (to chat with others), and my web server. Everything else (calendar/contacts, IMAP, Syncthing, etc) stays behind my firewall, accessible only to internal hosts. I use wireguard on my Android phone to access these services seamlessly when I leave the house.

I've never bothered to conceal my IP address. For awhile, I experimented with using Mullvad VPN for all my egress traffic. Unfortunately I spent all day solving CAPTCHAs...wasn't worth it (for me, anyway).

EDIT: I should add, that I also have a "normie" email address at one of the usual providers that I use for really important things like bank accounts / utility providers. If I get hit by a bus, I don't want my (very nontechnical) wife to deal with sysadminning on top of my early death.

For all our personal communications though, we use my selfhosted email domain.

[glandium]

A static, public IP address with a good reputation (ie, not on any spam blacklists)

Piece of cake /s

[PuffinBlue]

It's not that hard to do. Harder for residential address blocks for sure. But if you do all the other things previously mentioned like SPF/DKIM etc then cleaning up an IP address isn't that hard.

The only service we've ever had issues with is Outlook as they'll ban whole block for opaque reasons and we just escalate it to the provider and they sort it. We just moved two self-hosted mail servers to new IP addresses and there were only 2 lists to clear them from, which was a fill in form style automated process to resolve.

There's always SES (or other service of choice) as a backup for sending anyway if you notice something getting blocked. It's easy to switch to that for a day or two whilst you resolve an issue - though I must admit I think we only had to do that once in the last 12 months.

Maybe I'm breaking some kind of sysadmin code here and I don't realise it's a secret that self-hosting email isn't that hard? Am I supposed to keep up the myth that it is? :-) Any greybeards here please let me know!

[technothrasher]

I played around a bit with sending via SES and Sendgrid. I generally found that deliverability on either of those was actually worse than even one of my slightly dirty IPs.

[justinclift]

Maybe try with smtp2go?

Previously, I was also using Sendgrid as well. But they seemed to start doing the "growth at any costs" bullshit which for an email sending company means accepting and delivering spam. (Regardless of their PR/weasel-words these places use to deny it, that's what it comes down to). Thus lots of places now just drop all mail that comes from Sendgrid, no workaround.

When that happened, a friend pointed me to smtp2go, which I've used since personally and we now use at work. We haven't (yet) had anything blocked as spam (less than 10k emails sent a month though), so it seems like they've not done the "growth at any costs" bullshit like Sendgrid.

[PuffinBlue]

You're not the first person I've heard say that. It's interesting that we haven't faced that issue. I wonder if we'll get a nasty surprise the next time we try as it has been a while since the last time we did it.

[glandium]

There are entire datacenters blocked by some blocklist providers. Like, AFAIK, the OVH ones.

[justinclift]

Also note that it's super easy to configure postfix (and likely others) to send all outbound email via a third party service.

I personally use smtp2go.com, and was on their free tier for ages (now upgraded via work). Can recommend, as it "just works" and avoids all the mucking around with SPF/DKIM/etc.

Oh, on a similar note, definitely avoid Sendgrid if you want to send email via a third party. They're outright blocked (as a spam source) by way too many places to be considered reliable any more. :(

[ryjo]

Thanks for the info. This all sounds pretty reasonable.

[Joker_vD]

> DKIM records and proper signing of outgoing messages (DMARC records help too)

I've read somewhere that spammers started to use DKIM (or was it DMARC?) records faster than the legitimate web-mail providers.

[LeonM]

DKIM and DMARC are not anti-spam techniques per se. They are used to verify that the message is authentic, and that sender is authorized to send email on behalf of the domain.

If the sender is passing as an authorized sender (DMARC aligned), then the receiver has a pretty good indication the email is legit and that the sender was delegated to sent email on behalf of the domain. If the email is then classified as spam (based on its contents), then it is easier for the receiver to choose whether to adjust the reputation of the domain (in case of DMARC alignment), or the IP (if not aligned).

A DKIM signature and DMARC alignment is no guarantee that the email passes spam filters. The whole point of DMARC is to give the receiver as much information as possible to make a confident decision on the legitimacy of the email, and the reputability of a domain.

DMARC and DKIM works both ways, if you are sending legit email (not spam), it will improve your deliverability, but if you are in fact spamming then DMARC will reduce your deliverability (as it should).