It's an e-mail application.
Claws Mail is free and open-source. My current avatar is the Claws Mail logo. I now use it under both Linux and Windows. The Windows version is included as part of
GPG4Win. Screenshots are available at the Claws Mail web site.
You can add POP3, IMAP4, NNTP (newsgroups) accounts as well add a Gmail account (adding it either as a POP3 or IMAP4 account), it's loaded with features. I mentioned in another thread that Fulvio started regarding a mail problem, one of the features is that it can display a log of the network connection to the server, in the event of any errors retrieving mail. The log info should indicate what the problem was (wrong password, error on the server end, etc.) WIth plugins that can be loaded in, it can also display HTML e-mails, but such e-mails are first displayed as text by default and another plugin can filter out spam, once the user initially marks e-mails as spam or (for good mail) ham.
Claws Mail's history dates back to the Sylpheed e-mail application (which is also available for Linux and Windows, Claws Mail was known as Sylpheed-Claws back then. As time went on, it branched off on its own.
UserAgent: Mozilla/5.0 (X11; U; Linux i686; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Ubuntu/10.10 Chromium/9.0.597.107 Chrome/9.0.597.107 Safari/534.13