Claws Mail is a powerful and full-featured mail client formerly called Sylpheed-Claws. The appearance and interface are designed to be familiar to new users coming from other popular email clients, as well as experienced users. Almost all commands are accessible with the keyboard.
The software is intended to be light-weight and it has a similar interface to that of Sylpheed’s.
It is also extensible using loadable plugins, which can provide support for additional features, such as other storage formats, feed reader, calendar management, mail filtering, etc.
Key Features
- Multiple accounts.
- Threaded display.
- Filtering.
- Mime attachments.
- Usenet news reading and posting.
- SSL over POP3, SMTP, IMAP4rev1 and NNTP protocols.
- GnuPG support (with GPGME).
- User-defined headers.
- Colour labels.
- Multiple MH folder support.
- Mbox import/export.
- External editor.
- Message queueing and drafting.
- Automated mail checking.
- Line-wrapping.
- Clickable URIs.
- Addressbook.
- Printing.
- Plugin mechanism.
- Actions.
- Templates.
- Built-in image viewer.
- Face and X-Face headers support.
- Reply-finder.
- Fast message cache system.
- Per-folder processing mechanism.
- Spell checking (with aspell).
- Drag’n’drop support.
- POP before SMTP authentication.
- Automatic saving of message when composing.
- Handling of Unix signals.
- Control by command-line.
- Built-in GDB crash handler.
- Customisable toolbars.
- Powerful Quick Search function.
- ‘Dynamic’ signatures.
- Font configuration.
- Themes mechanism (see available themes).
- Automatic account selection.
- Message scoring.
- Ability to hide read messages.
- IMAP over SSH Tunnel.
- IMAP: CAPABILITY support.
- Return-Receipt handling.
- Message priority setting.
- ‘Ignore thread’ option.
- Anti-phishing URL check.
- Configurable notification of new mail.
- 7bit and 8bit encoding of attachments.
- NNTP: auto-mark cross-posted messages.
- Configurable (non-)display of images.
- Full coloration of messages.
- User-definable quotation characters.
- Watch marked threads.
- Log window.
- Reply to part of an email.
- Replied and forwarded flags.
- Man page and documentation.
- Full GnuPG support.
- ‘On-the-fly’ changing of the type of GnuPG encryption and/or signing used (MIME/ascii).
- Compose window.
- Manual selection of MIME type and encoding for attachments.
- Save all attachments in a mail at once.
- Save 2 or more selected files to a single file.
- SSL certificate management.
- User-definable newsgroup names abbreviation length.
- Address book: import from LDIF, Mutt or Pine natively.
- Address book: import from other mailers via scripts.
- Auto-completion of recipients (also via LDAP).
- Harvest addresses for addressbook.
- Addressbook export to various formats.
Website: www.claws-mail.org
Support: Documentation
Developer: Colin Leroy, Paul Mangan, Holger Berndt, Tristan Chabredier, Hoa viet Dinh, Keith Edmunds, Match Grun, Melvin Hadasht, and many others
License: GNU General Public License v3.0

Claws Mail is written in C. Learn C with our recommended free books and free tutorials.
Related Software
| Graphical Email Clients | |
|---|---|
| Thunderbird | Popular free, cross-platform e-mail, RSS and newsgroup client |
| Kmail | Email component of Kontact |
| Sylpheed | Simple, lightweight client |
| Mailspring | New version of Nylas Mail |
| Claws Mail | Lightweight yet powerful and full-featured client |
| Evolution | Provides integrated mail, addressbook and calendaring functionality |
| Geary | Mail client for GNOME written in Vala |
| Astroid | Lightweight and fast Mail User Agent |
| Balsa | Email client for GNOME |
| Also known as Pantheon Mail | |
| Dodo | Based on the command line email swiss-army-knife notmuch |
| Aerion | Standalone lightweight e-mail client inspired by Geary |
Read our verdict in the software roundup.
| Lightweight Email Clients | |
|---|---|
| Sylpheed | Client also based on the GTK+ GUI toolkit |
| Claws Mail | Powerful, user-friendly, fast and full-featured mail client based on GTK+ |
| Geary | Lightweight mail client for GNOME that is written in Vala |
| Astroid | Lightweight and fast Mail User Agent |
| Trojitá | Qt-based IMAP email client |
| Aerion | Lightweight e-mail client inspired by Geary |
Read our verdict in the software roundup.
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It would help if you tell the reader if it finds all the connections automatically like Thunderbird.
There is a link for the documentation inside. If this is really a go or nogo, klick on it. And then, in the first part you could read: “When you click the “Auto-configure” button, Claws Mail will attempt to configure your account’s servers based on your email address and the type of account you have chosen. ”
But this depends of your provider. On my MailServers this doesnt work, not for Thunderbird either.
I am using Claws for a lot of years and for me it is really the best. Fast and secure, super easy to make a full backup of all relevant parts, so also restore is easy.