<s>
AS1	B-Protocol
(	O
Applicability	B-Protocol
Statement	I-Protocol
1	I-Protocol
)	O
is	O
a	O
specification	B-Application
about	O
how	O
to	O
transport	O
structured	O
business-to-business	O
data	O
securely	O
and	O
reliably	O
over	O
the	O
Internet	O
.	O
</s>
<s>
The	O
AS1	B-Protocol
protocol	O
is	O
based	O
on	O
SMTP	O
and	O
S/MIME	B-Protocol
.	O
</s>
<s>
If	O
the	O
original	O
AS1	B-Protocol
message	O
requested	O
an	O
MDN	O
...	O
</s>
<s>
If	O
there	O
are	O
any	O
problems	O
receiving	O
or	O
interpreting	O
the	O
original	O
AS1	B-Protocol
message	O
,	O
a	O
"	O
failed	O
"	O
MDN	O
may	O
be	O
sent	O
back	O
.	O
</s>
<s>
Like	O
any	O
other	O
AS	O
file	O
transfer	O
,	O
AS1	B-Protocol
file	O
transfers	O
typically	O
require	O
both	O
sides	O
of	O
the	O
exchange	O
to	O
trade	O
X.509	O
certificates	O
and	O
specific	O
"	O
trading	O
partner	O
"	O
names	O
before	O
any	O
transfers	O
can	O
take	O
place	O
.	O
</s>
