<s>
Exchange	B-Protocol
ActiveSync	I-Protocol
(	O
commonly	O
known	O
as	O
EAS	O
)	O
is	O
a	O
proprietary	O
protocol	O
designed	O
for	O
the	O
synchronization	O
of	O
email	O
,	O
contacts	O
,	O
calendar	O
,	O
tasks	O
,	O
and	O
notes	O
from	O
a	O
messaging	O
server	B-Application
to	O
a	O
smartphone	B-Application
or	O
other	O
mobile	B-Application
devices	I-Application
.	O
</s>
<s>
The	O
protocol	O
also	O
provides	O
mobile	B-Application
device	I-Application
management	O
and	O
policy	O
controls	O
.	O
</s>
<s>
The	O
protocol	O
is	O
based	O
on	O
XML	B-Protocol
.	O
</s>
<s>
The	O
mobile	B-Application
device	I-Application
communicates	O
over	O
HTTP	B-Protocol
or	O
HTTPS	B-Protocol
.	O
</s>
<s>
Originally	O
branded	O
as	O
AirSync	B-Protocol
and	O
only	O
supporting	O
Microsoft	B-Operating_System
Exchange	I-Operating_System
Servers	I-Operating_System
and	O
Pocket	B-Device
PC	I-Device
devices	O
,	O
Microsoft	O
now	O
licenses	O
the	O
technology	O
widely	O
for	O
synchronization	O
between	O
groupware	B-Application
and	O
mobile	B-Application
devices	I-Application
in	O
a	O
number	O
of	O
competing	O
collaboration	B-Application
platforms	I-Application
,	O
including	O
:	O
</s>
<s>
GroupWise	B-Operating_System
with	O
the	O
Novell	B-Operating_System
GroupWise	I-Operating_System
Mobility	O
Services	O
software	O
,	O
</s>
<s>
Lotus	B-Operating_System
Notes	I-Operating_System
with	O
IBM	B-Application
Notes	I-Application
Traveler	I-Application
,	O
</s>
<s>
Mailsite	B-Protocol
,	O
</s>
<s>
MDaemon	B-Protocol
Email	I-Protocol
Server	I-Protocol
.	O
</s>
<s>
Google	B-Application
in	O
paid	O
Google	B-Application
Apps	I-Application
for	I-Application
Work	I-Application
subscriptions	O
from	O
2013	O
.	O
</s>
<s>
In	O
addition	O
to	O
support	O
on	O
Windows	B-Protocol
Phone	I-Protocol
,	O
EAS	O
client	O
support	O
is	O
included	O
on	O
:	O
</s>
<s>
Android	B-Application
,	O
</s>
<s>
iOS	B-Application
,	O
</s>
<s>
BlackBerry	B-Application
10	I-Application
smartphones	B-Application
and	O
the	O
BlackBerry	B-Application
PlayBook	I-Application
tablet	O
computer	O
.	O
</s>
<s>
Beyond	O
on	B-General_Concept
premises	I-General_Concept
installations	O
of	O
Exchange	O
,	O
the	O
various	O
personal	O
and	O
enterprise	O
hosted	O
services	O
from	O
Microsoft	O
also	O
utilize	O
EAS	O
,	O
including	O
Outlook.com	B-Operating_System
and	O
Office	B-Operating_System
365	I-Operating_System
.	O
</s>
<s>
The	O
built-in	O
email	O
application	O
for	O
Windows	B-Application
8	I-Application
desktop	O
,	O
Mail	B-Operating_System
app	O
,	O
also	O
supports	O
the	O
protocol	O
.	O
</s>
<s>
macOS	B-Application
,	O
in	O
the	O
native	O
Apple	B-Operating_System
Mail	I-Operating_System
app	O
.	O
</s>
<s>
The	O
first	O
version	O
of	O
EAS	O
(	O
called	O
AirSync	B-Protocol
at	O
the	O
time	O
)	O
was	O
a	O
part	O
of	O
Mobile	O
Information	O
Server	B-Application
(	O
MIS	O
)	O
2002	O
.	O
</s>
<s>
This	O
version	O
of	O
EAS	O
communicated	O
over	O
Web-based	B-Protocol
Distributed	I-Protocol
Authoring	I-Protocol
and	I-Protocol
Versioning	I-Protocol
(	O
WebDAV	B-Protocol
)	O
to	O
Exchange	O
2000	O
servers	O
syncing	O
Email	O
,	O
contacts	O
,	O
and	O
calendar	O
and	O
allowed	O
users	O
to	O
select	O
a	O
folder	O
list	O
to	O
sync	O
but	O
this	O
was	O
only	O
for	O
email	O
folders	O
(	O
not	O
contacts	O
or	O
calendars	O
)	O
.	O
</s>
<s>
This	O
initial	O
version	O
of	O
EAS	O
has	O
the	O
user	O
’s	O
device	O
“	O
pull	O
”	O
data	O
down	O
rather	O
than	O
have	O
the	O
server	B-Application
“	O
push	O
”	O
new	O
information	O
as	O
soon	O
as	O
it	O
was	O
available	O
.	O
</s>
<s>
EAS	O
2.0	O
shipped	O
in	O
Exchange	B-Operating_System
Server	I-Operating_System
2003	O
.	O
</s>
<s>
This	O
version	O
of	O
the	O
protocol	O
was	O
developed	O
by	O
the	O
Microsoft	O
Windows	O
Mobile	O
team	O
and	O
was	O
delivered	O
as	O
a	O
binary	O
drop	O
(	O
massync.dll	O
)	O
to	O
the	O
Exchange	B-Operating_System
Server	I-Operating_System
team	O
.	O
</s>
<s>
EAS	O
used	O
WebDAV	B-Protocol
to	O
connect	O
to	O
a	O
user	O
's	O
mailbox	O
and	O
added	O
the	O
ability	O
to	O
sync	O
non-default	O
calendar	O
and	O
contacts	O
folders	O
.	O
</s>
<s>
Always	O
Up	O
To	O
Date	O
(	O
AUTD	O
)	O
was	O
implemented	O
as	O
a	O
way	O
to	O
let	O
a	O
device	O
know	O
if	O
there	O
was	O
new	O
information	O
for	O
it	O
and	O
Short	O
Message	O
Service	O
(	O
SMS	B-Device
)	O
was	O
the	O
technology	O
used	O
to	O
deliver	O
this	O
information	O
to	O
the	O
device	O
.	O
</s>
<s>
Because	O
of	O
the	O
use	O
of	O
SMS	B-Device
as	O
a	O
notification	O
,	O
the	O
configuration	O
of	O
an	O
SMS	B-Device
gateway	O
was	O
required	O
and	O
each	O
account	O
needed	O
to	O
be	O
configured	O
with	O
a	O
user	O
's	O
mobile	O
phone	O
number	O
.	O
</s>
<s>
In	O
Exchange	B-Operating_System
Server	I-Operating_System
2003	O
SP1	O
ghosting	O
support	O
was	O
added	O
to	O
EAS	O
2.1	O
.	O
</s>
<s>
Ghosting	O
tells	O
server	B-Application
what	O
they	O
can	O
sync	O
and	O
then	O
all	O
is	O
sent	O
down	O
but	O
when	O
changes	O
are	O
sent	O
up	O
,	O
only	O
specified	O
fields	O
are	O
changed	O
(	O
others	O
are	O
not	O
deleted	O
)	O
.	O
</s>
<s>
EAS	O
2.5	O
(	O
Part	O
of	O
Exchange	B-Operating_System
Server	I-Operating_System
2003	O
SP2	O
)	O
was	O
the	O
first	O
version	O
of	O
EAS	O
to	O
be	O
written	O
by	O
the	O
Exchange	B-Operating_System
Server	I-Operating_System
team	O
.	O
</s>
<s>
This	O
version	O
also	O
introduced	O
Direct	O
Push	O
,	O
a	O
real-time	O
push	O
e-mail	O
solution	O
which	O
allows	O
the	O
server	B-Application
to	O
say	O
"	O
I	O
have	O
a	O
new	O
item	O
for	O
you	O
"	O
and	O
then	O
tells	O
the	O
client	O
device	O
to	O
do	O
a	O
sync	O
.	O
</s>
<s>
Tasks	O
syncing	O
was	O
added	O
as	O
was	O
S/MIME	B-Protocol
email	O
encryption	O
and	O
the	O
following	O
policies	O
were	O
added	O
:	O
</s>
<s>
EAS	O
12.0	O
came	O
with	O
Exchange	B-Operating_System
Server	I-Operating_System
2007	O
.	O
</s>
<s>
New	O
features	O
included	O
password	O
reset	O
which	O
allowed	O
users	O
to	O
reset	O
a	O
forgotten	O
PIN	O
lock	O
code	O
,	O
message	O
flagging	O
which	O
gave	O
users	O
the	O
ability	O
to	O
mark	O
a	O
message	O
so	O
they	O
could	O
remember	O
to	O
follow	O
up	O
on	O
it	O
when	O
they	O
got	O
back	O
to	O
their	O
computer	O
,	O
Out	O
of	O
Office	O
setting	O
so	O
users	O
could	O
set	O
an	O
“	O
away	O
”	O
message	O
from	O
their	O
phone	O
,	O
SharePoint	O
(	O
and	O
UNC	O
file	O
share	O
)	O
access	O
from	O
links	O
in	O
email	O
(	O
file	O
traffic	O
was	O
proxied	O
though	O
EAS	O
)	O
,	O
Empty	O
deleted	O
items	O
to	O
allow	O
people	O
to	O
shrink	O
their	O
mailboxes	O
so	O
they	O
did	O
n’t	O
exceed	O
their	O
mailbox	O
size	O
limits	O
,	O
fetch	O
which	O
allowed	O
users	O
to	O
get	O
only	O
parts	O
of	O
a	O
message	O
and	O
then	O
choose	O
later	O
to	O
get	O
the	O
rest	O
of	O
the	O
message	O
(	O
or	O
an	O
attachment	O
)	O
later	O
,	O
device	O
info	O
which	O
allowed	O
users	O
and	O
administrators	O
to	O
see	O
which	O
phones	O
were	O
connected	O
to	O
their	O
accounts	O
,	O
and	O
AutoDiscover	O
which	O
(	O
although	O
strictly	O
speaking	O
is	O
n’t	O
part	O
of	O
the	O
EAS	O
protocol	O
)	O
allowed	O
phones	O
to	O
automatically	O
configure	O
the	O
EAS	O
connection	O
with	O
just	O
a	O
user	O
login	O
and	O
password	O
(	O
instead	O
of	O
requiring	O
people	O
to	O
know	O
the	O
computer	O
name	O
of	O
their	O
Exchange	B-Operating_System
Server	I-Operating_System
)	O
.	O
</s>
<s>
The	O
ability	O
to	O
see	O
who	O
was	O
invited	O
to	O
a	O
meeting	O
was	O
also	O
added	O
as	O
well	O
as	O
the	O
ability	O
to	O
search	O
the	O
server	B-Application
for	O
an	O
email	O
that	O
was	O
not	O
synced	O
to	O
the	O
device	O
.	O
</s>
<s>
EAS	O
12.1	O
came	O
in	O
Exchange	B-Operating_System
Server	I-Operating_System
2007	O
SP1	O
.	O
</s>
<s>
This	O
version	O
of	O
the	O
protocol	O
was	O
one	O
of	O
the	O
largest	O
changes	O
since	O
version	O
2.5	O
and	O
featured	O
header	O
compression	O
(	O
Base64	B-Protocol
encoding	I-Protocol
of	O
a	O
binary	O
structure	O
)	O
to	O
decrease	O
the	O
amount	O
of	O
data	O
sent	O
wirelessly	O
,	O
Multiple	O
collections	O
sync	O
(	O
a	O
bundling	O
of	O
all	O
sync	O
requests	O
together	O
instead	O
of	O
the	O
previous	O
way	O
of	O
doing	O
a	O
sync	O
for	O
each	O
folder	O
separately	O
)	O
,	O
a	O
hanging	O
sync	O
which	O
allowed	O
the	O
server	B-Application
to	O
keep	O
a	O
communications	O
channel	O
open	O
to	O
the	O
client	O
at	O
all	O
times	O
so	O
battery	O
life	O
and	O
data	O
would	O
n’t	O
be	O
consumed	O
constantly	O
turning	O
on	O
the	O
radio	O
and	O
querying	O
the	O
server	B-Application
and	O
was	O
a	O
“	O
true	O
push	O
sync	O
”	O
solution	O
(	O
which	O
had	O
far	O
lower	O
message	O
delivery	O
latencies	O
,	O
as	O
opposed	O
to	O
the	O
previous	O
ping	O
based	O
“	O
push	O
to	O
pull	O
”	O
solution	O
)	O
,	O
a	O
confirmation	O
of	O
a	O
completed	O
remote	O
wipe	O
,	O
as	O
well	O
as	O
the	O
following	O
30	O
new	O
policies	O
:	O
</s>
<s>
EAS	O
14.0	O
was	O
introduced	O
as	O
part	O
of	O
Exchange	B-Operating_System
Server	I-Operating_System
2010	O
.	O
</s>
<s>
This	O
new	O
version	O
added	O
a	O
new	O
conversation	O
view	O
that	O
put	O
email	O
messages	O
in	O
a	O
view	O
connected	O
by	O
several	O
attributes	O
including	O
a	O
Message-ID	O
and	O
the	O
email	O
subject	O
,	O
notes	O
syncing	O
,	O
the	O
ability	O
to	O
look	O
up	O
the	O
availability	O
(	O
free/busy	O
status	O
)	O
of	O
a	O
contact	O
(	O
from	O
their	O
calendar	O
)	O
,	O
a	O
Nickname	O
Cache	O
which	O
shared	O
the	O
names	O
of	O
common	O
used	O
contacts	O
between	O
Outlook	B-Protocol
Web	I-Protocol
App	I-Protocol
(	O
OWA	O
)	O
and	O
EAS	O
,	O
the	O
ability	O
to	O
set	O
a	O
server	B-Application
side	O
rule	O
to	O
always	O
move	O
messages	O
in	O
a	O
conversation	O
,	O
lunar	O
calendar	O
support	O
,	O
syncing	O
of	O
the	O
reply	O
state	O
(	O
which	O
let	O
the	O
device	O
and	O
the	O
server	B-Application
know	O
if	O
any	O
message	O
had	O
been	O
forwarded	O
or	O
replied	O
to	O
from	O
any	O
other	O
source	O
)	O
,	O
a	O
new	O
way	O
to	O
identify	O
unified	O
messaging	O
(	O
UM	O
)	O
messages	O
so	O
that	O
voicemail	O
that	O
appeared	O
in	O
a	O
user	O
’s	O
inbox	O
could	O
be	O
handled	O
differently	O
,	O
SMS	B-Device
Syncing	O
(	O
which	O
allowed	O
users	O
to	O
see	O
their	O
SMS	B-Device
messages	O
in	O
their	O
email	O
inbox	O
and	O
reply	O
to	O
them	O
from	O
their	O
inbox	O
instead	O
of	O
on	O
their	O
phone	O
)	O
,	O
and	O
the	O
following	O
two	O
new	O
policies	O
:	O
</s>
<s>
EAS	O
14.1	O
came	O
as	O
part	O
of	O
Exchange	B-Operating_System
Server	I-Operating_System
2010	O
SP1	O
.	O
</s>
<s>
This	O
version	O
of	O
the	O
protocol	O
added	O
(	O
images	O
stored	O
in	O
an	O
Active	O
Directory	O
server	B-Application
of	O
the	O
user	O
who	O
has	O
sent	O
the	O
email	O
)	O
,	O
Message	O
Diffs	O
(	O
a	O
means	O
of	O
sending	O
only	O
the	O
new	O
portion	O
of	O
an	O
email	O
and	O
avoiding	O
redundant	O
information	O
)	O
,	O
added	O
device/user	O
information	O
to	O
the	O
provision	O
command	O
so	O
that	O
the	O
new	O
Allow/Block/Quarantine	O
feature	O
could	O
more	O
easily	O
allow	O
administrators	O
to	O
control	O
which	O
devices	O
connected	O
to	O
their	O
organizations	O
,	O
and	O
information	O
rights	O
management	O
(	O
IRM	O
)	O
over	O
EAS	O
(	O
a	O
method	O
to	O
apply	O
digital	O
rights	O
management	O
control	O
and	O
encryption	O
to	O
email	O
messages	O
that	O
are	O
sent	O
and	O
received	O
)	O
.	O
</s>
<s>
EAS	O
16.0	O
was	O
announced	O
in	O
June	O
2015	O
and	O
was	O
deployed	O
in	O
Office	B-Operating_System
365	I-Operating_System
first	O
,	O
followed	O
by	O
Exchange	B-Operating_System
Server	I-Operating_System
2016	O
.	O
</s>
<s>
EAS	O
16.1	O
was	O
announced	O
in	O
June	O
2016	O
and	O
was	O
deployed	O
in	O
Office	B-Operating_System
365	I-Operating_System
first	O
,	O
followed	O
by	O
Exchange	B-Operating_System
Server	I-Operating_System
2016	O
.	O
</s>
<s>
Various	O
other	O
organizations	O
licensed	O
EAS	O
over	O
time	O
and	O
Microsoft	O
eventually	O
started	O
licensing	O
the	O
server	B-Application
side	O
of	O
EAS	O
in	O
2007	O
.	O
</s>
<s>
Google	B-Application
uses	O
an	O
implementation	O
of	O
EAS	O
for	O
its	O
G	B-Application
Suite	I-Application
subscribers	O
.	O
</s>
<s>
Likewise	O
,	O
IBM	O
and	O
Novell	O
have	O
implemented	O
the	O
technology	O
to	O
allow	O
their	O
competing	O
groupware	B-Application
servers	O
(	O
Lotus	B-Operating_System
Domino	I-Operating_System
and	O
Novell	B-Operating_System
GroupWise	I-Operating_System
)	O
to	O
support	O
smartphones	B-Application
and	O
other	O
devices	O
,	O
through	O
IBM	B-Application
Notes	I-Application
Traveler	I-Application
and	O
Novell	O
Data	O
Synchronizer	O
Mobility	O
Pack	O
,	O
respectively	O
.	O
</s>
