Personally, I prefer Posteo. It’s cheap, it’s simple, the pricing is flat, and it’s fully open-source (and LibreJS compliant).

I haven’t tried Posteo, but I can vouch for Mailbox being absolutely amazing. I’ve been with them for years and picked them at the start of my degoogling journey. I was really happy to have a single service that took so much of google off my phone…email, contacts sync, calendar, online drive, etc etc.

I used mailbox.org for some time. They gradually removed features from their “basic” 1 euro plan until it was the same as posteo. So I moved to posteo.

@Sunshine I am using both right now. I like Posteo for its reliability, privacy, and sustainability ethos. I like Mailbox for its professional look and additional services. On the negative side, I find Posteo almost too simple. You can add more addresses and calendars for a fee but it can add up. For Mailbox, I have found their Spam filters are somewhat sensitive. Some OTPs and services not come through. Mailbox just does not send it to your junk folder but reject it outright.

1/2

Don’t forget Tuta and ProtonMail.

I’ve used both in the past but am now using neither. If being able to use a custom domain is a requirement then you really only have one option between these two: mailbox.org.

Neither of them truly “win” though and I wish people would stop it with these reductive questions.