<s>
A	O
Mailslot	B-Operating_System
is	O
a	O
one-way	O
interprocess	B-Operating_System
communication	I-Operating_System
mechanism	O
,	O
available	O
on	O
the	O
Microsoft	O
Windows	O
operating	O
system	O
,	O
that	O
allows	O
communication	O
between	O
processes	O
both	O
locally	O
and	O
over	O
a	O
network	B-Architecture
.	O
</s>
<s>
The	O
use	O
of	O
Mailslots	B-Operating_System
is	O
generally	O
simpler	O
than	O
named	B-Operating_System
pipes	I-Operating_System
or	O
sockets	B-Protocol
when	O
a	O
relatively	O
small	O
number	O
of	O
relatively	O
short	O
messages	O
are	O
expected	O
to	O
be	O
transmitted	O
,	O
such	O
as	O
for	O
example	O
infrequent	O
state-change	O
messages	O
,	O
or	O
as	O
part	O
of	O
a	O
peer-discovery	O
protocol	O
.	O
</s>
<s>
The	O
Mailslot	B-Operating_System
mechanism	O
allows	O
for	O
short	O
message	O
broadcasts	O
(	O
"	O
datagrams	O
"	O
)	O
to	O
all	O
listening	O
computers	O
across	O
a	O
given	O
network	B-Architecture
domain	O
.	O
</s>
<s>
Mailslots	B-Operating_System
function	O
as	O
a	O
server-client	O
interface	O
.	O
</s>
<s>
A	O
server	B-Application
can	O
create	O
a	O
Mailslot	B-Operating_System
,	O
and	O
a	O
client	B-Protocol
can	O
write	O
to	O
it	O
by	O
name	O
.	O
</s>
<s>
Only	O
the	O
server	B-Application
can	O
read	O
the	O
mailslot	B-Operating_System
,	O
as	O
such	O
mailslots	B-Operating_System
represent	O
a	O
one-way	O
communication	O
mechanism	O
.	O
</s>
<s>
A	O
server-client	O
interface	O
could	O
consist	O
of	O
two	O
processes	O
communicating	O
locally	O
or	O
across	O
a	O
network	B-Architecture
.	O
</s>
<s>
Mailslots	B-Operating_System
operate	O
over	O
the	O
RPC	O
protocol	O
and	O
work	O
across	O
all	O
computers	O
in	O
the	O
same	O
network	B-Architecture
domain	O
.	O
</s>
<s>
Mailslots	B-Operating_System
offer	O
no	O
confirmation	O
that	O
a	O
message	O
has	O
been	O
received	O
.	O
</s>
<s>
Mailslots	B-Operating_System
are	O
generally	O
a	O
good	O
choice	O
when	O
one	O
client	B-Protocol
process	O
must	O
broadcast	O
a	O
message	O
to	O
multiple	O
server	B-Application
processes	O
.	O
</s>
<s>
The	O
most	O
widely	O
known	O
use	O
of	O
the	O
Mailslot	B-Operating_System
IPC	O
mechanism	O
is	O
the	O
Windows	B-Protocol
Messenger	I-Protocol
service	I-Protocol
that	O
is	O
part	O
of	O
the	O
Windows	O
NT-line	O
of	O
products	O
,	O
including	O
Windows	B-Application
XP	I-Application
.	O
</s>
<s>
The	O
Messenger	B-Protocol
Service	O
,	O
not	O
to	O
be	O
confused	O
with	O
the	O
MSN	O
Messenger	B-Protocol
internet	O
chat	O
service	O
,	O
is	O
essentially	O
a	O
Mailslot	B-Operating_System
server	B-Application
that	O
waits	O
for	O
a	O
message	O
to	O
arrive	O
.	O
</s>
<s>
The	O
NET	B-Protocol
SEND	I-Protocol
command	O
is	O
therefore	O
a	O
type	O
of	O
Mailslot	B-Operating_System
client	B-Protocol
,	O
because	O
it	O
writes	O
to	O
specified	O
mailslots	B-Operating_System
on	O
a	O
network	B-Architecture
.	O
</s>
<s>
A	O
number	O
of	O
programs	O
also	O
use	O
Mailslots	B-Operating_System
to	O
communicate	O
.	O
</s>
<s>
Commercial	O
programs	O
usually	O
prefer	O
pipes	O
or	O
sockets	B-Protocol
.	O
</s>
<s>
Mailslots	B-Operating_System
are	O
implemented	O
as	O
files	O
in	O
a	O
mailslot	B-Operating_System
file	O
system	O
(	O
MSFS	O
)	O
.	O
</s>
<s>
Examples	O
of	O
Mailslots	B-Operating_System
include	O
:	O
</s>
