I want to thank everyone who replied. I did some research on most of these and think PurelyMail is the winner for me. Feel free to correct me if I got some details wrong. I want to give a shoutout to @mbirth for mentioning Disroot, which looks like a really interesting experiment in federated services.
Also, I know this post is really bending the rules for c/selfhosted, but connecting your selfhosted services to an email provider is essential, and having a reliable and affordable email provider just makes this weird hobby of ours a little easier.
| My Rating (1-5) | Service | Website | Annual Cost | Only Email? |
|---|---|---|---|---|
| 5 | PurelyMail | https://purelymail.com/ | $10, pay for added storage | Yes |
| 4 | MXRoute | https://mxroute.com/ | $50/year small plan | Yes |
| 4 | Disroot | https://disroot.org/ | Free, pay to add storage and domains | Yes, separated from other Disroot services |
| 3 | Fastmail | https://www.fastmail.com/ | $60 individual plan | Yes-ish |
| 3 | Mailo | https://www.mailo.com/ | ~$14 premium plan | No |
| 3 | Proton | https://mail.proton.me/ | $48/year plus plan $120/year unlimited plan | No |
| 2 | Mailbox.org | https://mailbox.org/ | ~$14 light plan ~$42 standard | Light plan |
| 2 | Migadu | https://migadu.com/ | $90 mini plan | Yes |
| 1 | GMX | https://www.gmx.com/mail/ | Free, ad supported | No |