# S-nail vs Sup

- S-nail: Command-line mail program that implements POSIX mailx, with MIME, IMAP, POP3, SMTP, Maildir and S/MIME support.
- Sup: Curses email client in Ruby built around threads, labels and fast full-text search over local mail.

## Differences

- S-nail is a command-line program; Sup is a full-screen terminal client.
- Only S-nail has built-in IMAP, POP3 and SMTP.
- On BSD, S-nail runs natively and Sup builds from source.
- Sup has OpenPGP; S-nail does not.
- S-nail has S/MIME; Sup does not.
- S-nail has OAuth2 sign-in; Sup does not.
- Sup has Vim-style keys; S-nail does not.
- S-nail is written in C; Sup in Ruby.
- Configuration: S-nail uses ~/.mailrc command file, and Sup uses ~/.sup/config.yaml and ~/.sup/sources.yaml, plus Ruby hooks.

## Side by side

| | S-nail | Sup |
| --- | --- | --- |
| Interface | Command-line tools and prompts | Full-screen terminal interface |
| Language | C | Ruby |
| License | ISC and BSD 2-Clause and BSD 3-Clause and BSD 4-Clause | GPL 2.0 or later |
| Linux | Native | Native |
| macOS | Native | Native |
| Windows | Through WSL | Through WSL |
| BSD | Native | Build from source |
| Android | Not supported | Not supported |
| IMAP | Yes | No |
| POP3 | Yes | No |
| SMTP | Yes | Through a separate tool |
| JMAP | No | No |
| Maildir | Yes | Yes |
| mbox | Yes | Yes |
| notmuch | No | No |
| OpenPGP | No | Yes |
| S/MIME | Yes | No |
| OAuth2 sign-in | via script | No |
| Threads | Yes | Yes |
| Search | built-in message specifications and the search command; IMAP SEARCH on IMAP folders | Xapian full-text index with a query language |
| HTML mail | built-in tag-soup filter or external viewer via mailcap | via the mime-decode hook and an external viewer such as w3m |
| Mouse | No | No |
| Multiple accounts | Yes | Yes |
| Offline use | IMAP cache with disconnected mode | reads local Maildir or mbox; sync with isync or OfflineIMAP |
| Calendar | No | No |
| Contacts | aliases via the alias command | tracks recent contacts automatically |
| Vim-style keys | No | Yes |
| Configuration | ~/.mailrc command file | ~/.sup/config.yaml and ~/.sup/sources.yaml, plus Ruby hooks |

Pages: [S-nail](https://terminalemail.com/clients/s-nail/index.md), [Sup](https://terminalemail.com/clients/sup/index.md)