XThunderbird is an extension that provides a full-featured email client, RSS and newsgroup client. It supports different mail accounts (POP, IMAP, Gmail). It has an email account setup wizard, an address book, a user interface with tabs, an integrated spam filter, advanced search, indexing capabilities, and provides an email organization using tags and virtual folders. The Thunderbird online main features are: - Message management that can handle several email, newsgroup, and news feed accounts using functionalities such as quick search, message filtering, message grouping, and set labels to find messages. - Junk filtering that includes a spam filter. - Protocols supported: POP and IMAP, but it also supports LDAP address completion, RSS/Atom reader, S/MIME and OpenPGP standards for secure email. - File formats supported: mbox, Unix mailbox format; and maildir, known as maildir-lite. - Mail Account Setup Wizard, so only providing the name, email address, and password the wizard will check an internal database and find the proper email settings. - Multiple-channel chat to have real-time conversation with contacts, and supporting multiple networks. - Activity Manager that records all the interactions between Thunderbird and your email provider in one place. - NetNews client integrated. - Multiple folders support. - Import / export mailboxes. - Include message queueing. - Contact management and vCard support. - Support APOP authentication. - Support SMTP AUTH.