<s>
Zimbra	O
Collaboration	O
,	O
formerly	O
known	O
as	O
the	O
Zimbra	O
Collaboration	O
Suite	O
(	O
ZCS	O
)	O
before	O
2019	O
,	O
is	O
a	O
collaborative	B-Application
software	I-Application
suite	O
that	O
includes	O
an	O
email	B-Protocol
server	I-Protocol
and	O
a	O
web	O
client	B-Protocol
.	O
</s>
<s>
The	O
company	O
was	O
subsequently	O
purchased	O
by	O
Yahoo	B-Application
!	I-Application
</s>
<s>
The	O
software	O
consists	O
of	O
both	O
client	B-Protocol
and	O
server	B-Application
components	O
,	O
and	O
at	O
one	O
time	O
also	O
offered	O
a	O
desktop	O
email	B-Protocol
client	I-Protocol
,	O
called	O
Zimbra	O
Desktop	O
.	O
</s>
<s>
Two	O
versions	O
of	O
Zimbra	O
are	O
available	O
:	O
an	O
open-source	B-Application
version	O
,	O
and	O
a	O
commercially	O
supported	O
version	O
(	O
"	O
Network	O
Edition	O
"	O
)	O
with	O
closed-source	B-Application
components	O
such	O
as	O
a	O
proprietary	B-Application
Messaging	B-Protocol
Application	I-Protocol
Programming	I-Protocol
Interface	I-Protocol
connector	O
to	O
Outlook	O
for	O
calendar	O
and	O
contact	O
synchronisation	O
.	O
</s>
<s>
The	O
now	O
discontinued	O
Zimbra	O
Desktop	O
was	O
a	O
full-featured	O
free	O
desktop	O
email	B-Protocol
client	I-Protocol
.	O
</s>
<s>
The	O
web	O
client	B-Protocol
featured	O
an	O
HTML5	O
offline	O
mode	O
starting	O
with	O
version	O
8.5	O
.	O
</s>
<s>
The	O
Zimbra	O
Web	O
Client	B-Protocol
is	O
a	O
full-featured	O
collaboration	O
suite	O
that	O
supports	O
email	O
and	O
group	O
calendars	O
.	O
</s>
<s>
At	O
one	O
time	O
it	O
featured	O
document-sharing	O
using	O
an	O
Ajax	B-General_Concept
web	O
interface	O
that	O
enabled	O
tool	O
tips	O
,	O
drag-and-drop	O
items	O
,	O
and	O
right-click	O
menus	O
in	O
the	O
UI	O
.	O
</s>
<s>
Also	O
included	O
are	O
advanced	O
searching	O
capabilities	O
and	O
date	O
relations	O
,	O
online	O
document	O
authoring	O
,	O
"	O
Zimlet	O
"	O
mashups	B-Application
,	O
and	O
a	O
full	O
administration	O
UI	O
.	O
</s>
<s>
It	O
is	O
written	O
using	O
the	O
Zimbra	O
Ajax	B-General_Concept
Toolkit	O
.	O
</s>
<s>
The	O
Zimbra	O
Server	B-Application
uses	O
several	O
open	O
source	O
projects	O
(	O
see	O
the	O
section	O
,	O
Included	O
open	O
source	O
projects	O
)	O
.	O
</s>
<s>
It	O
exposes	O
a	O
SOAP	B-Protocol
application	B-Application
programming	I-Application
interface	I-Application
to	O
all	O
its	O
functionality	O
and	O
is	O
also	O
an	O
IMAP	B-Protocol
and	O
POP3	B-Protocol
server	B-Application
.	O
</s>
<s>
The	O
server	B-Application
runs	O
on	O
many	O
Linux	B-Application
distributions	I-Application
.	O
</s>
<s>
On	O
other	O
,	O
non-Linux	O
operating	O
systems	O
it	O
can	O
be	O
run	O
using	O
a	O
virtual	B-Architecture
machine	I-Architecture
and	O
using	O
container	O
technology	O
.	O
</s>
<s>
Zimbra	O
uses	O
Postfix	B-Application
for	O
its	O
MTA	O
functionality	O
.	O
</s>
<s>
It	O
includes	O
technology	O
from	O
ClamAV	B-Application
,	O
SpamAssassin	B-Language
and	O
DSPAM	O
for	O
anti-malware	O
features	O
and	O
S/MIME	O
for	O
email	O
signing	O
and	O
encryption	O
.	O
</s>
<s>
OS	B-Operating_System
X	I-Operating_System
Server	I-Operating_System
support	O
was	O
dropped	O
with	O
version	O
ZCS	O
7.0	O
.	O
</s>
<s>
Zimbra	O
can	O
synchronize	O
mail	O
,	O
contacts	O
,	O
and	O
calendar	O
items	O
with	O
open-source	B-Application
mail	B-Protocol
clients	I-Protocol
such	O
as	O
Mozilla	B-Application
Thunderbird	I-Application
and	O
Evolution	B-Language
and	O
also	O
with	O
proprietary	B-Application
clients	O
such	O
as	O
Microsoft	B-Application
Outlook	I-Application
and	O
Apple	B-Operating_System
Mail	I-Operating_System
,	O
either	O
through	O
proprietary	B-Application
connectors	O
or	O
using	O
the	O
ActiveSync	B-Operating_System
protocol	O
,	O
both	O
available	O
exclusively	O
in	O
the	O
commercially	O
supported	O
version	O
.	O
</s>
<s>
The	O
closed	B-Application
source	I-Application
variant	O
Network	O
edition	O
is	O
distributed	O
under	O
the	O
Zimbra	O
Network	O
Edition	O
EULA	O
.	O
</s>
<s>
Starting	O
with	O
version	O
8.5	O
the	O
Zimbra	O
source	O
code	O
is	O
available	O
under	O
the	O
terms	O
of	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
version	O
2	O
(	O
backend	O
)	O
and	O
the	O
Common	B-License
Public	I-License
Attribution	I-License
License	I-License
version	O
1	O
(	O
frontend	O
)	O
.	O
</s>
<s>
Previous	O
versions	O
were	O
released	O
under	O
the	O
Zimbra	B-License
Public	I-License
License	I-License
(	O
ZPL	O
)	O
.	O
</s>
<s>
The	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
accepts	O
the	O
license	O
as	O
being	O
a	O
free	B-License
software	I-License
license	I-License
and	O
refers	O
to	O
it	O
as	O
being	O
identical	O
to	O
the	O
Yahoo	B-Application
!	I-Application
</s>
<s>
Public	O
License	O
with	O
the	O
exception	O
that	O
Zimbra	O
,	O
Inc	O
.	O
provides	O
the	O
license	O
,	O
rather	O
than	O
Yahoo	B-Application
!	I-Application
.	O
</s>
<s>
The	O
Zimbra	O
Server	B-Application
uses	O
open	O
source	O
projects	O
such	O
as	O
:	O
</s>
