• One of the most requested Mozilla Mail features, an option to separate the Recipient and Sender columns in the thread pane, has been implemented.
• Another frequently requested MailNews feature, a preference for placing the user's signature above the quoted text, has been added.
• "Remove from server after x days" has been implemented for POP3 mail accounts.
• vCard support has been added to Mozilla Mail.
• Mozilla 1.6 includes a new cross-platform NTLM authentication mechanism. This feature brings NTLM authentication to the non-Windows Mozilla users for the first time and also delivers more robust and featureful NTLM support to users of older Windows versions.
• Ask Jeeves searching has been added to Mozilla 1.6.
• "Translate Page" functionality has returned to this release of Mozilla.
• The View Source window now has reload functionality.
• Several security-related bugs were fixed in 1.6
• Chatzilla 0.9.48 has been merged, which adds RPL_ISUPPORT support, halfop mode support, and properly masks key and password dialogs.
• Many crash bugs have been fixed.
• One step closer to the kitchen sink, about:about has been implemented. Typing about:about in the address field will give the user a nice list of available about:s.

These are items that have been added to the Known Issues page since the last milestone, although the bugs themselves may have existed previously.

• File | Compact Folders for imap accounts now compacts all imap folders in the account, and their offline stores, if any folders are configured for offline use. Previously, this command just compacted the selected folder. To compact just the selected folder, you should now use the folder context menu command Compact this Folder. (Bug 230672)
• On non-Windows systems, pasting in Composer and HTML message compose from the first character of the line can fail. (Bug 228688)