Side by side
Carbon Mail vs Sup
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 Web
Carbon Mail combines Gmail access with action-oriented sorting, writing assistance, and on-device protections. Its current focus is desktop, with mobile companions not yet available.
Visit Carbon Mail Free plan LinuxMac
Sup offers deep local organization and customization for users comfortable with console email tools. Its platform limits and imperfect synchronization with other clients should be considered before adoption.
Visit SupThe facts
| Carbon Mail | Sup | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Not published |
| Runs on | Web | Linux, Mac |
| Lowest paid plan | Free or on request | Free or on request |
| Plans published | 2 | 1 |
| Maker | Not published | Not published |
| Website | carbonmail.app | supmua.dev |
| On email clients | #97 of 142 | #101 of 142 |
Carbon Mail: what it does well
- Connects to an existing Gmail account
- Sorts messages into action-based categories
- Provides on-device writing and summary tools
- Includes phishing and lookalike-domain warnings
- Fully featured free tier
What to know first
- Focused on desktop use
- Mobile companions are planned for late 2026
- Requires an existing Gmail account
- No native mobile availability is listed
Sup: what it does well
- Fast local full-text email search
- Hierarchical threads with multiple tags
- Multiple account support
- Ruby customization hooks
- Full GPG support
What to know first
- Windows is not supported
- May not synchronize all changes
- May conflict with other mail clients
- Console-based interface
Alternatives to Carbon Mail Alternatives to Sup The whole list