Side by side
Opterius Mail vs SIEVER Mail
Both stand on email clients. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free plan Self-hostedWeb
Opterius Mail combines a full webmail client with optional server administration and hosting-panel integration. Its self-hosted nature and operating-system requirements matter for deployment planning.
Visit Opterius Mail Free plan LinuxMacWindows
SIEVER Mail focuses on multi-account desktop email with local storage, search, organization, and privacy-oriented handling. Its active-development status and build-time extension model may matter to users seeking a settled platform.
Visit SIEVER MailThe facts
| Opterius Mail | SIEVER Mail | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Not published |
| Runs on | Self-hosted, Web | Linux, Mac, Windows |
| Lowest paid plan | Free or on request | Not published |
| Plans published | 2 | None |
| Maker | Opterius Mail | Not published |
| Website | opterius.com | github.com |
| On email clients | #90 of 142 | #94 of 142 |
Opterius Mail: what it does well
- Free forever under AGPL-3.0
- Supports major IMAP and SMTP servers
- Webmail and administration modes
- DKIM, SPF, DMARC, and MX checks
- Responsive interface without separate app
What to know first
- Requires self-hosted deployment
- Installation supports only listed Linux versions
- Designed around existing mail-server infrastructure
- Administration features require admin mode
SIEVER Mail: what it does well
- Supports multiple IMAP/SMTP accounts
- Unified inbox for supported accounts
- Local SQLite mail storage
- No telemetry or third-party tracking
- Linux, macOS, and Windows support
What to know first
- No paid plans or trial listed
- Project remains in active development
- One build-time extension limit
- No web or mobile client listed
Alternatives to Opterius Mail Alternatives to SIEVER Mail The whole list