YunoHost
Host your own email, files, calendars, and passwords on a single server with YunoHost, a server operating system that puts every app behind one web admin and one shared login. Browse a catalog of more than 500 apps, such as Nextcloud, WordPress, and Vaultwarden, filter by quality level, and install in a few clicks, or paste a Git URL for a custom app. Each person signs in once at a portal that shows a tile for every app they may open, and apps with single sign-on skip their own login screen. Groups and per-app permissions control access, including public access for visitors, and the Admins group adds web admin, SSH, and sudo. A full mail stack handles incoming and outgoing email per domain with DKIM signing, and Let's Encrypt certificates renew automatically. The domain screen suggests the DNS records you need and can push them to a supported registrar's API, while free .nohost.me, .noho.st, and .ynh.fr subdomains configure themselves. Backups bundle system settings, mail data, and chosen apps into downloadable archives that can be restored selectively from the admin or the command line. Twice a day a built-in diagnosis checks DNS records, mail setup, and system resources, then emails the admins if anything needs attention, with a firewall editor and fail2ban protection alongside. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.
maddy
Running a proper mail server used to mean stitching together half a dozen daemons; maddy folds the whole stack into one binary with one configuration file. It receives mail as your MX, sends as your MTA, stores messages for IMAP clients, and signs and verifies with DKIM, SPF, DMARC, DANE, and MTA-STS so other servers actually trust what you send. The design is composable: checks, modifiers, tables, and delivery targets snap together in the config, so spam scoring, address rewriting, and routing rules read like a pipeline instead of a pile of interlocking config files. Outbound mail queues with retries and backoff, inbound delivery lands in IMAP storage backed by SQLite or PostgreSQL, and a built-in ACME client keeps TLS certificates renewed, including DNS-01 providers. Milter support lets existing filters join the pipeline, authentication spans SASL mechanisms and Dovecot delegation, and Prometheus metrics watch queue length and delivery health from your usual dashboards. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed.