I've self-hosted with a hand-rolled postfix+dovecot, and later with Mailcow's dockerised mailserver (FOSS, good management and webmail UI, strongly recommend).

More recently though I moved my personal domain to Microsoft Exchange Online - it's a lot less flexible than Mailcow (per-head licensing, but there's + addressing and catch-alls now) but I don't have any of the deliverability/gmail-spam-folder issues I used to have.

Exchange P1 Online [2] is roughly the same for my single-user as my old DO droplet cost per month

(edit: side-bonus you get an Azure AD tenant for your domain which is handy for SSO/IdP things)

[1]: https://mailcow.email/

[2]: https://www.microsoft.com/en-au/microsoft-365/exchange/compa...