What is Claws Mail?

Claws Mail is an e-mail client (& news reader) based on GTK+, running on the X Window System, and aiming for

Quick response

Graceful, and sophisticated interface

Easy configuration, intuitive operation

Abundant features

Extensibility

Robustness and stability

Where can I get Claws Mail?

See the Downloads page https://www.claws-mail.org/downloads.php.

Who writes Claws Mail?

Claws Mail is developed by the Claws Mail Team.

How does Claws Mail store mails?

Mails are stored in the MH mailfile format as used by MH and EMH. Maildir and mbox format are supported via two plugins available on the Plugins page.

Where does Claws Mail store mails?

By default, Claws Mail stores mails in $HOME/Mail.

The location of mail folders is defined in $HOME/.claws-mail/folderlist.xml

To point Claws Mail at an alternative mail store, select File -> Add Mailbox and specify the path to the mail folder. Claws Mail will scan for sub-folders automatically.

Does Claws Mail have mail filtering?

Yes. You can find it in Configuration->Filtering... tab.

Can Claws Mail handle local unix mailboxes?

Yes.

Can Claws Mail handle IPv6?

Yes, IPv6 is fully supported in Claws Mail.

How many POP3, News or IMAP accounts can I set up in Claws Mail?

The number is unlimited. The limit is reached when your computer stops responding.

Can I set up an Account for sending Mail only?

Yes, set up a new account using Configuration -> Create new Account and set the Protocol to None (SMTP only). Or create a local Account for a MH-directory and disable automatic checking for new mail on that account.

Does Claws Mail support encryption like GPG?

Yes. GPG is implemented and works fine. For activating it in Claws Mail, see the Installation and Configuration section.

How does Claws Mail check for MIME types?

Claws Mail uses the Mutt type of mime checking.

Does Claws Mail allow me to write HTML styled messages?

No. A discussion has gone around over this topic, and the outcome was that HTML mail is not wanted. If you really need to send HTML, you can of course attach a webpage to an e-mail.

Does Claws Mail have name completion in the address fields?

Yes. When you search for a name that starts with "don", type "don" (without the quotes) and press the TAB key. This will show you the correct name (when only one "don" exists in your addressbook. Otherwise a dropdown list appears, which allows you to select the name you want. E.g. Donald Duck, Don Johnson. But also e-mail addresses starting with "don" will appear in the list (like "don.giovanni@maffia.org").

Why is Claws Mail so fast?

That's what it is designed for!

How can I send in patches, report bugs, talk about Claws Mail with others?

To talk to others, you should join the Claws Mail users' mailing list at https://www.claws-mail.org/MLs.php.

Can I import an mbox into Claws Mail's MH mailfolders?

Yes, just create/select the folder you want your mails in, and select "Import mbox file" in the File menu.

Can I use procmail to sort my mails with the MH mail handling?

Yes. Just make sure that you add /. to the end of a rule so procmail knows that you are filtering into an MH mail folder. Example :

0: * ^Subject:.*claws clawsmail/.

Check man procmail for details.

When I upgrade Claws Mail, are there things I should be aware of?

Yes, some more critical than others.

You should always read the RELEASE_NOTES document that is included in the release tarballs. The release notes can also be viewed on the Claws Mail News page and in the '/Help/About' dialogue in Claws Mail itself.

Just press Ctrl+Alt+U or select "/View/Update summary" from the main menu.

Why does Claws Mail allow me to open more than one instance at the same time for the same user on a network?

Claws Mail opens a Unix-domain socket using a name constucted from your TMPDIR path plus your UID. This socket is used to arbitrate multiple instances on a given machine. In Linux, at least, named Unix-domain sockets are known only locally, to the creating machine. Pointing your TMPDIR environment variable to /home/yours/tmp doesn't have the desired effect, as the socket definition would need to be propagated across the LAN and isn't.

Setting an alternate configuration directory (--alternate-config-dir option) overrides TMPDIR value and places the socket under the alternate directory.

Does Claws Mail have an anti-spam feature?

Yes. It has a Bogofilter plugin and a SpamAssassin plugin. You can find details of them on the Plugins FAQ Page.

You can also use other spam filters via Actions, futher details can be found on the Using Claws Mail with other programs page.

Does Claws Mail support Return Receipts?

Yes.

To request a Return Receipt use '/Options/Request Return Receipt' in the Compose window.

When you receive a message that requests a Return Receipt a notification area is shown just above the message view. You can either use the 'Send receipt' button, or ignore the request - no receipts are sent automatically.

You can choose to never send Return Receipts by using the option on the Mail Handling/Sending page of the Preferences. When you use this option, all Return Receipt requests are ignored and you will not be prompted to send one.

Why does Claws Mail load big folders slowly?

Certain options, although handy, can slow down Claws Mail. Consider disabling the following options to achieve more speed:

/Display/Summaries 'Display sender using address book'

/Display/Summaries 'Thread using subject in addition to standard headers'

/Plugins/GPG 'Automatically check signatures'

In the Message List, Sort by Date or other non-string headers instead of Subject, From or To.

Avoid using cpu intensive folder Processing rules conditions such as "Whole message", "Body part", etc, and Pre/Post processing.

How do I make a new Icon Theme for Claws Mail?

Obviously you need to have some artistic abilities (well, not much unless you want to make a really cool theme), but, apart from that, there's some technical points you should consider when making a new theme and you want to share it with the rest of the world:

Choose a license for it. Remember that themes without license are not free.

If you're using some other theme or graphic element you found on the web be careful and check its license also. Some authors use strange licenses which does not allow derivations or redistributions, or impose the original license over derived works.

If you're making original artwork and do not know (or care) which license to choose, GPL is a good and recommended option. It's the same license that Claws Mail uses.

Try to provide a full set of icons. The easiest way to do that is to copy all Claws Mail icons and start editing them.

Keep the sizes uniform. Claws Mail default icons are certain size, and some variations are allowed, but size disparity can not be a good idea if two icons are going to be displayed side to side.

Provide a .claws_themeinfo file

Have a look at the existing themes, they may inspire you! :)

Why does the users' mailing list get mail from the bug tracker?

Mail from the bug tracker gets delivered to the users' mailing list because it is believed and/or hoped that subscribers, as Claws Mail users, can help in bug reporting. Be that confirming, suggesting solutions, or whatever.

Feature requests also delivered via the bug tracker, and this makes everyone aware of the requests, and enables everyone to voice an opinion on the usefulness of such a feature.

All in all, it's about getting user involvement, and opening up an aspect of development to conversation, however slight that might turn out to be in practice.

What are the differences between Claws Mail and Sylpheed?

Back in 2001 Claws Mail (formerly Sylpheed-Claws) started as the bleeding-edge version of Sylpheed, in order to act as a testbed for new features for Sylpheed. The idea was to regularly resync with Hiroyuki's main branch, and vice-versa. Claws Mail then evolved into the stable, extended version of Sylpheed, and in 2006 became an entity in its own right, in part due to different goals and the fact that syncing both codebases stopped happening.

Claws Mail has many extra features compared to Sylpheed and is more powerful, yet is just as fast, lightweight and stable.