Sylpheed-Claws includes most of the main branch's features, such as:

Multiple accounts Threaded display Filtering Mime attachments Usenet news reading and posting SSL over POP3, SMTP, IMAP4rev1 and NNTP protocols GnuPG support (with GPGME) Build-in image viewer X-Face support User-defined headers Colour labels Multiple MH folder support Mbox import/export External editor Message queueing and drafting Automated mail checking Templates Line-wrapping Clickable URIs XML-based addressbook Printing

Claws-only features

The following features are not currently found in main Sylpheed:

Plugin mechanism Reply-finder New message cache system New sort function New filtering/processing mechanism Spell checking (with aspell) Powerful Extended Search MH/IMAP/MBOX folder drag 'n' drop support POP before SMTP authentication Automatic saving of message when composing Automatic message drafting and cache saving on kill Built-in GDB crash handler Customisable toolbars Quick search function 'Dynamic' signatures Font configuration Icon theming Automatic account selection Message scoring Ability to hide read messages IMAP over SSH Tunnel IMAP: UIDPLUS extension support. IMAP: CAPABILITY support. Request Return-Receipt Extra Folder properties: Return-receipt Save messages Default To: Subject simplification Folder CHMOD Default account Folder colour Revised compose window 'Ignore thread' option Improved clickable URL support URI parser accepts mailto URLs with a '?' Configurable notification of new mail 7bit and 8bit encoding of attachments NNTP: auto-mark cross-posted messages Configurable (non-)display of images Signature in the message view can be coloured User-definable quotation characters Indication of unread answers to marked mails: '(!)' is appended to the folder name when a marked message has a response Display url in statusbar on single-click online/offline modes --online and --offline command-line switches Message priority setting Controllable size of log text in log window Ability to select part of a text mime-part to reply Reply and forward flags get set on sending message Sylpheed man page GnuPG users are informed of expired signatures and keys GnuPG signed messages are indicated by an icon in the Attachment column 'On-the-fly' changing of the type of GnuPG encryption and/or signing used (MIME/ascii) in the Compose window Manual selection of MIME type and encoding for attachments Allow user to 'Save all' attachments in a mail with multiple attachments Save 2 or more selected files to a single file Cc and Bcc Template definitions SSL certificate management Logging can be stopped User-definable newsgroup names abbreviation length Manual and FAQ remote and local links Actions: trailing ">" syntax to insert command's output without replacing old text (in contrast to trailing "|") Address book: import Mutt addressbook Address book: import Pine addressbook Address book copy and paste Support for LDAP dynamic queries Harvest addresses for addressbook Export addressbook to html file Address book: 'Edit Group Details' dialog allows multiple selection in either pane .mh_sequences file is created in new MH folders


The following plugins are included in the source package.

Clam AntiVirus Enables the scanning of message attachments in mail received from a POP, IMAP, or LOCAL account using Clam AntiVirus. It can optionally delete the mail or save it to a designated folder. Clam AntiVirus is available from

Dillo HTML Viewer Enables the viewing of html messages using the Dillo web browser, version 0.7.0 or newer. It uses Dillo's --local option by default for safe browsing. Dillo is available from

Image Viewer (GTK1 only, built-in for GTK2) Enables viewing of attached images and replaces the previous built-in image viewer. Preferences can now be found in '/Configuration/Preferences/Message View/ Image Viewer'. If the option 'Automatically display attached images' is not set, the user is presented with a 'Load Image' button in the messageview and information about the file. This plugin requires either gdk-pixbuf or imlib.

MathML Viewer Enables the viewing of attachments that have the Content-Type 'text/mathml' using the GtkMathView widget which is available from

PGP/Core Handles core PGP functions and is a dependency of both the PGP/Inline and PGP/MIME plugins. Requires GnuPG and GPGME,

PGP/Inline Handles PGP/Inline signed and/or encrypted mails. You can decrypt mails, verify signatures or sign and encrypt your own mails. Requires GnuPG and GPGME,

PGP/MIME Handles PGP/MIME signed and/or encrypted mails. You can decrypt mails, verify signatures or sign and encrypt your own mails. Requires GnuPG and GPGME,

SpamAssassin Enables the scanning of incoming mail received from a POP, IMAP, or LOCAL account using SpamAssassin. It can optionally delete mail identified as spam or save it to a designated folder. SpamAssassin is available from Configure option: --enable-spamassassin-plugin

Trayicon Places an icon in the system tray that indicates whether you have any new mail. A tooltip also shows the current new, unread and total number of messages


A 'Tools' directory is also included which holds various scripts. Most of these scripts can also be used with main Sylpheed and, for this reason, they are also available here for individual download.