<s>
Push-IMAP	B-Protocol
,	O
which	O
is	O
otherwise	O
known	O
as	O
P-IMAP	B-Protocol
or	O
Push	O
extensions	O
for	O
Internet	B-Protocol
Message	I-Protocol
Access	I-Protocol
Protocol	I-Protocol
,	O
is	O
an	O
email	O
protocol	O
designed	O
as	O
a	O
faster	O
way	O
to	O
synchronise	O
a	O
mobile	O
device	O
like	O
a	O
PDA	B-Application
or	O
smartphone	B-Application
to	O
an	O
email	O
server	O
.	O
</s>
<s>
It	O
was	O
developed	O
by	O
Oracle	B-Application
and	O
other	O
partners	O
,	O
and	O
based	O
on	O
IMAP	B-Protocol
with	O
additional	O
enhancements	O
for	O
optimization	O
in	O
a	O
mobile	O
setting	O
.	O
</s>
<s>
It	O
was	O
submitted	O
as	O
input	O
to	O
the	O
Lemonade	B-Protocol
Profile	I-Protocol
IETF	O
Working	O
Group	O
-	O
but	O
was	O
not	O
included	O
in	O
the	O
resulting	O
RFC	O
4550	O
.	O
</s>
<s>
The	O
protocol	O
was	O
designed	O
to	O
provide	O
for	O
a	O
secure	O
way	O
to	O
automatically	O
keep	O
communicating	O
new	O
messages	O
between	O
a	O
server	O
and	O
a	O
mobile	O
device	O
like	O
a	O
PDA	B-Application
or	O
Smartphone	B-Application
.	O
</s>
<s>
Additionally	O
,	O
P-IMAP	B-Protocol
features	O
a	O
mechanism	O
for	O
sending	O
email	O
that	O
is	O
derived	O
from	O
(	O
but	O
not	O
identical	O
to	O
)	O
SMTP	B-Protocol
,	O
and	O
so	O
a	O
rich	O
email	O
service	O
is	O
provided	O
using	O
a	O
single	O
connection	O
.	O
</s>
<s>
P-IMAP	B-Protocol
should	O
not	O
be	O
viewed	O
as	O
an	O
alternative	O
to	O
the	O
IMAP	B-Protocol
IDLE	I-Protocol
command	O
(	O
RFC	O
2177	O
)	O
.	O
</s>
<s>
In	O
fact	O
,	O
IDLE	O
is	O
one	O
of	O
the	O
required	O
mechanisms	O
for	O
a	O
P-IMAP	B-Protocol
server	O
to	O
notify	O
the	O
client	O
(	O
optional	O
notifications	O
are	O
SMS	B-Device
or	O
WAP	O
Push	O
)	O
.	O
</s>
<s>
Although	O
they	O
are	O
both	O
based	O
on	O
IMAP	B-Protocol
,	O
the	O
Yahoo	O
!	O
</s>
<s>
Mail	O
and	O
iCloud	B-Application
push	B-General_Concept
email	I-General_Concept
services	O
for	O
iPhone	B-Device
do	O
not	O
use	O
a	O
standard	O
form	O
of	O
P-IMAP	B-Protocol
.	O
</s>
<s>
Mail	O
uses	O
a	O
special	O
UDP	B-Protocol
message	O
to	O
trigger	O
an	O
email	O
synchronization	O
,	O
while	O
Apple	O
's	O
iCloud	B-Application
push	B-General_Concept
email	I-General_Concept
uses	O
a	O
variant	O
of	O
XMPP	B-Protocol
.	O
</s>
