8.5.1 is IBM's most significant upgrade in years.

New Lotus Notes 8.5.1 features:

• View emails by conversation (like a discussion thread)
• Prebuilt and custom widgets
• Ability to consolidate multiple calendars
• Message recall
• Improved look and feel

• ID Vault - lets administrators reset passwords without access to the ID file itself.
• DAOS (Domino Attachment and Object service), saves an attachment once even if it has been sent to multiple users. Space saving will vary based on a number of factors but organisations should expect at least a 25-30% reduction in disk space.