Install AcelleMail on Ubuntu 24.04 LTS

Hetzner works fine, the article is DO-flavored only because that's what I had open when I wrote it. Nothing in the install steps is provider-specific past "Ubuntu 24.04 with root". One note on the PTR: on Hetzner Cloud you can usually set rDNS yourself from the server's Networking tab without a ticket. If yours needed a ticket you're probably on a Robot dedicated box, which is a different panel. Worth checking before you wait a day. I'll add a short "provider notes" bit covering rDNS on both, since PTR is the thing that actually decides whether your first sends land.

No headless flag yet, the wizard is the only supported fresh install. Workaround is to run it once on a throwaway box and treat the resulting .env plus DB as your artifact.

No real reason, MariaDB is fine. The guides say MySQL 8 mostly because that's what we test on, not because anything in the app depends on it. It's a stock Laravel schema, no MySQL-specific features, and we have plenty of installs running MariaDB. Two things worth checking on your side: use utf8mb4 with utf8mb4_unicode_ci for the database (subscriber names and campaign subjects will mangle otherwise), and stay on a reasonably recent MariaDB. Very old versions get grumpy about index key length on the longer varchar columns during migration. If you hit anything MariaDB-specific during install, tell me the version and the error and I'll add a note to the article. Right now it doesn't mention MariaDB at all, which is probably why the question comes up.