<s>
Sylpheed	B-Language
is	O
an	O
open-source	B-Application
e-mail	B-Protocol
client	I-Protocol
and	O
news	B-Protocol
client	I-Protocol
licensed	O
under	O
GNU	B-License
GPL-2.0-or-later	I-License
with	O
the	O
library	O
part	O
LibSylph	O
under	O
GNU	B-Application
LGPL-2.1-or-later	I-Application
.	O
</s>
<s>
It	O
stores	O
mail	O
in	O
the	O
MH	B-Protocol
Message	I-Protocol
Handling	I-Protocol
System	I-Protocol
.	O
</s>
<s>
Sylpheed	B-Language
runs	O
on	O
Unix-like	B-Operating_System
systems	I-Operating_System
such	O
as	O
Linux	B-Application
or	O
BSD	B-Operating_System
,	O
and	O
it	O
is	O
also	O
usable	O
on	O
Windows	B-Application
.	O
</s>
<s>
It	O
uses	O
GTK+	B-Application
.	O
</s>
<s>
In	O
2005	O
,	O
Sylpheed	B-Language
was	O
forked	O
to	O
create	O
Sylpheed-Claws	B-Language
,	O
now	O
known	O
as	O
Claws	B-Language
Mail	I-Language
.	O
</s>
<s>
Sylpheed	B-Language
is	O
the	O
default	O
mail	B-Protocol
client	I-Protocol
in	O
Lubuntu	B-Application
,	O
Damn	B-Operating_System
Small	I-Operating_System
Linux	I-Operating_System
and	O
some	O
flavours	O
of	O
Puppy	O
Linux	B-Application
.	O
</s>
<s>
Sylpheed	B-Language
provides	O
support	O
for	O
spam	O
filtering	O
using	O
either	O
bogofilter	B-Protocol
or	O
bsfilter	O
,	O
at	O
the	O
user	O
's	O
choice	O
.	O
</s>
<s>
Bsfilter	O
is	O
shipped	O
with	O
the	O
Windows	B-Application
version	O
of	O
Sylpheed	B-Language
.	O
</s>
<s>
Sylpheed	B-Language
supports	O
the	O
development	O
of	O
plug-ins	O
.	O
</s>
<s>
As	O
of	O
February	O
2015	O
,	O
Sylpheed	B-Language
's	O
website	O
notes	O
an	O
attachment-tool	O
plug-in	O
,	O
an	O
automatic	O
mail	O
forwarding	O
plug-in	O
,	O
and	O
a	O
plug-in	O
for	O
determining	O
whether	O
or	O
not	O
attachments	O
are	O
password-protected	O
.	O
</s>
<s>
Sylpheed	B-Language
is	O
unable	O
to	O
send	O
HTML	O
mail	O
.	O
</s>
<s>
It	O
is	O
still	O
possible	O
to	O
receive	O
HTML	O
mail	O
using	O
Sylpheed	B-Language
.	O
</s>
<s>
The	O
password	O
is	O
stored	O
in	O
plaintext	O
in	O
the	O
Sylpheed	B-Language
configuration	O
file	O
,	O
which	O
by	O
default	O
is	O
only	O
readable	O
by	O
"	O
owner	O
"	O
and	O
not	O
by	O
"	O
group	O
"	O
nor	O
"	O
other	O
"	O
.	O
</s>
<s>
A	O
feature	O
called	O
"	O
master	O
password	O
"	O
prevents	O
Sylpheed	B-Language
from	O
holding	O
plaintext	O
passwords	O
,	O
but	O
does	O
not	O
protect	O
stored	O
messages	O
from	O
other	O
local	O
users	O
with	O
administrator	O
privilege	O
.	O
</s>
<s>
Sylpheed	B-Language
includes	O
natively	O
PGP	B-Application
Sign	O
and	O
PGP	B-Application
Encrypt	O
options	O
in	O
the	O
compose	O
window	O
(	O
which	O
requires	O
however	O
an	O
encryption	O
tool	O
based	O
on	O
PGP	B-Application
already	O
installed	O
on	O
the	O
computer	O
)	O
.	O
</s>
