A password manager because if anything goes wrong, you’ll be completely screwed.

What you SHOULD absolutely self host though is a password manager, so you can be in control of your most sensitive data.

Regarding email, I think everyone should absolutely self host it, but it’s less and less viable in this google/Microsoft duopoly world. But ideally everyone would self host it. The reason why people advise against it really comes down to lack of real competition, and the two tech giants dictating how we violate every RFC possible.

Don’t self-host email SMTP or public DNS. They’re hard to set up properly, hard to maintain, easy to compromise and end up used in internet attacks.

Don’t expose anything directly to the internet if you’re not willing to constantly monitor the vulnerability announcements, update to new releases as soon as they come out, monitor the container for intrusions and shenanigans, take the risk that the constant updates will break something etc. If you must expose a service use a VPN (Tailscale is very easy to set up and use.)

Don’t self-host anything with important data that takes uber-geek skills to maintain and access. Ask yourself, if you were to die suddenly, how screwed would your non-tech-savvy family be, who can’t tell a Linux server from a hot plate? Would they be able to keep functioning (calendar, photos, documents etc.) without constant maintenance? Can they still retrieve their files (docs, pics) with only basic computing skills? Can they migrate somewhere else when the server runs down?

E-mail

Don’t host your own email server.

Just trust me.

People saying email, look into using external SMTP servers as relays. Your domain most likely comes with at least one email account with SMTP access. You can use that as a relay to send personal/business emails from your server using the provider’s reputable IP addresses.

Passwords:
-> You want to have immediat access to them, even if your house burns down

Notes:
-> You want to be able to read the documentation how to fix your selfhosted service, even when your selfhosted services are down

Public Reverse proxy:
-> A reverse proxy is only as safe as the applications behind. And NO, most selfhosted-applications are not hardened or had security audits
(reverse proxy with a forward authentication proxy is something different)

I’d say backups. At least it shouldn’t be only local. I follow the rule of threes: two local copies and one off site with backblaze. Yeah, it ties up a not insignificant amount of disk space I could use for other things, but dammit, I’m not loosing my wedding photos, important system configurations, etc.

Okay I understand that email hosting is bad for SENDING email , but what about only RECEIVING email , isn’t it a good idea to keep my stuff private ? I rarely send personal emails, and like to avoid my data being used for marketing purposes Is that bad to have smtp imap open on dynamic ip address ? Just asking your opinion