<s>
An	O
Internet	B-Protocol
messaging	I-Protocol
platform	I-Protocol
is	O
any	O
system	O
on	O
the	O
Internet	O
that	O
exchanges	O
messages	O
for	O
the	O
purpose	O
of	O
human	O
communications	O
.	O
</s>
<s>
Messaging	O
platforms	O
are	O
considered	O
one	O
of	O
few	O
key	B-Architecture
Internet	I-Architecture
infrastructure	I-Architecture
elements	O
.	O
</s>
<s>
What	O
used	O
to	O
be	O
only	O
referred	O
to	O
as	O
email	O
and	O
IM	B-Application
has	O
evolved	O
into	O
a	O
complex	O
multi-media	O
email	O
,	O
instant	B-Application
messaging	I-Application
,	O
and	O
related	O
fixed	O
and	O
mobile	O
messaging	O
infrastructure	O
.	O
</s>
<s>
In	O
the	O
beginning	O
there	O
was	O
Sendmail	B-Application
and	O
many	O
other	O
mail	B-Protocol
delivery	I-Protocol
agents	I-Protocol
soon	O
followed	O
(	O
Postfix	B-Application
etc	O
.	O
)	O
</s>
<s>
These	O
critical	B-Architecture
Internet	I-Architecture
infrastructure	I-Architecture
systems	O
had	O
to	O
be	O
patched	O
and	O
the	O
underlying	O
protocols	O
changed	O
-or	O
in	O
some	O
cases	O
ignored	O
-	O
to	O
deal	O
with	O
these	O
issues	O
.	O
</s>
<s>
Large	O
telecommunication	O
operators	O
and	O
internet	O
service	O
providers	O
needed	O
flexible	O
,	O
easily	O
deployed	O
and	O
scaled	O
messaging	O
systems	O
for	O
quickly	O
growing	O
messaging	O
services	O
and	O
cell	O
phone	O
networks	O
(	O
for	O
examples	O
see	O
SMS	B-Device
and	O
BlackBerry	B-Operating_System
.	O
)	O
</s>
<s>
Smaller	O
operators	O
and	O
ISPs	O
have	O
generally	O
relied	O
on	O
open-source	O
software	O
,	O
like	O
Sendmail	B-Application
,	O
and	O
in-house	O
system	O
administrators	O
for	O
maintenance	O
.	O
</s>
