The open-source Roundcube replacement. Fast, beautiful, and works with any IMAP/SMTP server — Dovecot, Postfix, Exchange, and more.
Opterius Mail ships with every feature your users and infrastructure team need — from reading email to managing full mail domains.
Authenticates directly against any IMAP server. Dovecot, Courier, Exchange, Zimbra — no separate user database required.
Reply, forward, CC/BCC, inline signatures, save as draft. Contact autocomplete in the To/CC/BCC fields for fast addressing.
Create, rename, and delete IMAP folders directly from the sidebar. System folders (Sent, Drafts, Trash, Junk) are detected automatically.
Built-in address book with per-user contacts. Automatically suggests recipients while composing based on saved contacts.
Searches subject, sender, and message body across any folder via native IMAP UID SEARCH — no local index needed.
Add mail domains, run per-domain DNS health checks (MX, SPF, DMARC, DKIM) and get clear pass/fail badges for every record.
Full CRUD for mail accounts, aliases, and distribution groups. Set per-account quotas, enable/suspend accounts, manage autoresponders.
Generate RSA key pairs per domain and view the exact DNS TXT record to publish — all from a single admin screen.
HMAC-SHA256 signed SSO tokens allow Opterius Panel to log users directly into their webmail with a single click — no re-entering passwords.
Swap the entire UI with a custom template via a single env variable. Custom templates only need to override the views they change.
Sandboxed iframe HTML email rendering prevents XSS. IMAP credentials stored only in encrypted session — never written to the database.
Slide-out folder sidebar and fluid message list work seamlessly on phones and tablets. No separate mobile app required.
Run as a simple webmail client for existing infrastructure, or enable admin mode for complete mail server management.
Drop it in front of any existing IMAP/SMTP setup. Users log in with their email credentials — no local database, no registration, no configuration beyond the IMAP host.
Adds a full admin panel for managing domains, accounts, aliases, DKIM keys, spam settings, and the mail queue — while keeping the webmail experience identical for end users.
Roundcube is a solid, battle-tested mailer — but it was designed in the 2000s. Opterius Mail is built for the 2020s.
| Feature | Roundcube | Opterius Mail |
|---|---|---|
| Modern Tailwind UI | ||
| Built-in admin panel | ||
| DKIM key management | ||
| DNS health check (SPF, DMARC) | ||
| Panel SSO integration | ||
| Dark mode | ||
| Mobile-first responsive layout | ||
| Swappable template system | ||
| Universal IMAP support | ||
| Free & open source | ||
| License | Free (GPL) | Free (AGPL) |
Opterius Mail ships as the default webmail in Panel. One-click SSO, automatic account sync, and zero extra configuration.
The installer sets up Mail, configures Dovecot and Postfix integration, and drops ready-to-paste DNS snippets.
Supports Ubuntu 22.04 / 24.04, Debian 11/12, AlmaLinux 8/9, Rocky Linux 8/9
Free, open source, and installs in under five minutes. Your users will notice the difference on day one.