DeltaSync was a
proprietary Microsoft communications protocol for synchronizing web services with offline clients. It was switched off by Microsoft on 30 June 2016.
Windows Live Hotmail
Outlook.com is a webmail service that is part of the Microsoft 365 product family. It offers mail, calendaring, contacts, and tasks services.
Founded in 1996 by Sabeer Bhatia and Jack Smith as Hotmail, it was acquired by Microsoft in 19 ...
was connected to
offline clients using DeltaSync;
Outlook Connector
Microsoft Outlook is a personal information manager software system from Microsoft, available as a part of the Microsoft Office and Microsoft 365 software suites. Though primarily an email client, Outlook also includes such functions as Calen ...
and the
Windows Live Mail client use it for offline access. Microsoft pushed for this protocol instead of
POP3 or
IMAP4
In computing, the Internet Message Access Protocol (IMAP) is an Internet standard protocol used by email clients to retrieve email messages from a mail server over a TCP/IP connection. IMAP is defined by .
IMAP was designed with the goal ...
for supporting various advanced features, like contacts, calendar, and notes synchronization. Using the DeltaSync protocol, Microsoft intended to provide a common platform for any compatible device to implement a client which can two-way synchronize mail, contacts, calendar, and notes.
History
In January 2007, Microsoft announced DeltaSync as the replacement for
WebDAV. In April 2008, Microsoft sent an email warning that WebDAV would no longer be supported after 30 June 2008. However, in May 2008, Microsoft stated that it would be "postponing the transition deadline previously announced" to allow customers more time to "evaluate alternative solutions". In June 2009, Microsoft announced that WebDAV support would finally end on 1 September 2009.
Format details
The DeltaSync compression code produces a stream with a four byte magic number of "HU01", followed by the stream header.
HU01 header
Following this header is a series of compressed data blocks with the following structure.
SCBH header
This is followed by 256 bytes of decompression table and finally the actual compressed data.
Discontinuation
Since Microsoft migrated the
Outlook.com
Outlook.com is a webmail service that is part of the Microsoft 365 product family. It offers mail, Calendaring software, calendaring, Address book, contacts, and Task management, tasks services.
Founded in 1996 by Sabeer Bhatia and Jack Smit ...
mail to use a structure based on
Office 365, the DeltaSync protocol was discontinued on 30 June 2016, and mail will not be able to be synced using
Windows Live Mail after that time. Google's Gmail and some other providers' mail services still work with DeltaSync.
Although DeltaSync has sunk, Microsoft's Windows Live Mail 2011 and 2012 continue to work with Hotmail e-mail accounts, by using IMAP (or, less effectively, POP) in place of DeltaSync.
See also
*
Windows Live Hotmail
Outlook.com is a webmail service that is part of the Microsoft 365 product family. It offers mail, calendaring, contacts, and tasks services.
Founded in 1996 by Sabeer Bhatia and Jack Smith as Hotmail, it was acquired by Microsoft in 19 ...
*
Windows Live Mail
*
Microsoft Office Outlook
Microsoft Outlook is a personal information manager software system from Microsoft, available as a part of the Microsoft Office and Microsoft 365 software suites. Though primarily an email client, Outlook also includes such functions as cale ...
*
Microsoft Office Outlook Connector
Microsoft Outlook is a personal information manager software system from Microsoft, available as a part of the Microsoft Office and Microsoft 365 software suites. Though primarily an email client, Outlook also includes such functions as cale ...
References
External links
Daniel Parnell is reverse engineering DeltaSyncDaniel Parnell has released the source for DeltaSync decompression codeanother person reverse engineering DeltaSyncIndependently-supported Java implementation of DeltaSync
Windows Live
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