<s>
Opera	B-Operating_System
Mail	I-Operating_System
(	O
formerly	O
known	O
as	O
M2	B-Operating_System
)	O
is	O
the	O
email	B-Protocol
and	O
news	B-Protocol
client	I-Protocol
developed	O
by	O
Opera	B-Application
Software	O
.	O
</s>
<s>
It	O
was	O
an	O
integrated	O
component	O
within	O
the	O
Opera	B-Application
web	I-Application
browser	I-Application
from	O
version	O
2	O
through	O
12	O
.	O
</s>
<s>
With	O
the	O
release	O
of	O
Opera	B-Application
15	O
in	O
2013	O
,	O
Opera	B-Operating_System
Mail	I-Operating_System
became	O
a	O
separate	O
product	O
and	O
is	O
no	O
longer	O
bundled	O
with	O
Opera	B-Application
.	O
</s>
<s>
Opera	B-Operating_System
Mail	I-Operating_System
version	O
1.0	O
is	O
available	O
for	O
OS	B-Operating_System
X	I-Operating_System
and	O
Windows	O
.	O
</s>
<s>
It	O
features	O
rich	O
text	O
support	O
and	O
inline	O
spell	B-Application
checking	I-Application
,	O
spam	O
filtering	O
(	O
both	O
automated	O
and	O
Bayesian	B-Application
)	O
,	O
a	O
contact	B-Application
manager	I-Application
,	O
and	O
supports	O
POP3	B-Protocol
and	O
IMAP	B-Protocol
,	O
newsgroups	B-Application
,	O
and	O
Atom	B-Application
and	O
RSS	O
feeds	O
.	O
</s>
<s>
Opera	B-Operating_System
Mail	I-Operating_System
uses	O
one	O
database	O
that	O
keeps	O
an	O
index	O
of	O
all	O
mail	O
and	O
sorts	O
the	O
messages	O
automatically	O
into	O
several	O
"	O
views	O
"	O
or	O
access	O
points	O
.	O
</s>
<s>
Opera	B-Operating_System
Mail	I-Operating_System
can	O
also	O
use	O
Bayesian	B-Application
filtering	O
to	O
automatically	O
sort	O
messages	O
into	O
other	O
views	O
.	O
</s>
<s>
The	O
IRC	O
client	O
supported	O
multiple	O
servers	O
,	O
file	O
transfers	O
,	O
and	O
interface	O
customization	O
through	O
CSS	B-Language
.	O
</s>
<s>
Opera	B-Operating_System
Mail	I-Operating_System
can	O
display	O
text	O
and	O
HTML	B-Language
emails	O
and	O
uses	O
the	O
Presto	B-Application
layout	I-Application
engine	I-Application
to	O
display	O
HTML	B-Language
.	O
</s>
<s>
Opera	B-Operating_System
Mail	I-Operating_System
is	O
at	O
the	O
end-of-life	O
stage	O
of	O
its	O
product	O
lifecycle	O
;	O
this	O
means	O
neither	O
technical	O
support	O
nor	O
product	O
and	O
security	O
updates	O
will	O
be	O
provided	O
.	O
</s>
<s>
Users	O
of	O
Opera	B-Operating_System
Mail	I-Operating_System
who	O
have	O
large	O
amounts	O
of	O
email	B-Protocol
and	O
would	O
like	O
to	O
utilize	O
64-bit	O
performance	O
can	O
use	O
the	O
64-bit	O
build	O
of	O
the	O
Opera	B-Application
Web	I-Application
Browser	I-Application
,	O
which	O
is	O
the	O
same	O
code	O
contained	O
in	O
the	O
standalone	O
email	B-Protocol
client	I-Protocol
.	O
</s>
<s>
In	O
November	O
2020	O
,	O
Vivaldi	B-Language
has	O
launched	O
a	O
Technical	O
Preview	O
of	O
its	O
email	B-Protocol
client	I-Protocol
,	O
Vivaldi	B-Language
Mail	I-Language
which	O
many	O
users	O
have	O
considered	O
it	O
to	O
be	O
a	O
spiritual	O
successor	O
to	O
Opera	B-Operating_System
M2	I-Operating_System
.	O
</s>
