<s>
Apple	B-Operating_System
Mail	I-Operating_System
(	O
officially	O
known	O
as	O
Mail	O
)	O
is	O
an	O
email	B-Protocol
client	I-Protocol
included	O
by	O
Apple	O
Inc	O
.	O
with	O
its	O
operating	B-General_Concept
systems	I-General_Concept
macOS	B-Application
,	O
iOS	B-Application
,	O
iPadOS	B-Operating_System
and	O
watchOS	B-Device
.	O
</s>
<s>
Apple	B-Operating_System
Mail	I-Operating_System
grew	O
out	O
of	O
NeXTMail	O
,	O
which	O
was	O
originally	O
developed	O
by	O
NeXT	O
as	O
part	O
of	O
its	O
NeXTSTEP	B-Application
operating	B-General_Concept
system	I-General_Concept
,	O
after	O
Apple	O
's	O
acquisition	O
of	O
NeXT	O
in	O
1997	O
.	O
</s>
<s>
The	O
current	O
version	O
of	O
Apple	B-Operating_System
Mail	I-Operating_System
utilizes	O
SMTP	B-Protocol
for	O
message	O
sending	O
,	O
POP3	B-Protocol
,	O
Exchange	B-Operating_System
and	O
IMAP	B-Protocol
for	O
message	O
retrieval	O
and	O
S/MIME	B-Protocol
for	O
end-to-end	O
message	O
encryption	O
.	O
</s>
<s>
Mail	O
,	O
AOL	B-Application
Mail	I-Application
,	O
Gmail	B-Application
,	O
Outlook	B-Operating_System
and	O
iCloud	B-Application
(	O
formerly	O
MobileMe	B-Application
)	O
and	O
it	O
supports	O
Exchange	B-Operating_System
.	O
</s>
<s>
iOS	B-Application
features	O
a	O
mobile	O
version	O
of	O
Apple	B-Operating_System
Mail	I-Operating_System
with	O
added	O
Exchange	B-Protocol
ActiveSync	I-Protocol
(	O
EAS	O
)	O
support	O
,	O
though	O
it	O
notoriously	O
missed	O
the	O
functionality	O
of	O
attaching	O
files	O
to	O
reply	O
emails	O
until	O
the	O
release	O
of	O
iOS	B-Operating_System
9	I-Operating_System
.	O
</s>
<s>
EAS	O
is	O
not	O
supported	O
in	O
the	O
macOS	B-Application
version	O
of	O
Apple	O
's	O
Mail	O
app	O
,	O
the	O
main	O
issue	O
being	O
that	O
sent	O
messages	O
will	O
incorrectly	O
be	O
duplicated	O
in	O
the	O
sent	O
messages	O
folder	O
,	O
which	O
then	O
propagates	O
via	O
sync	O
to	O
all	O
other	O
devices	O
including	O
iOS	B-Application
.	O
</s>
<s>
Features	O
of	O
Apple	B-Operating_System
Mail	I-Operating_System
include	O
the	O
ability	O
to	O
configure	O
the	O
software	O
to	O
receive	O
all	O
of	O
a	O
user	O
's	O
email	O
accounts	O
in	O
the	O
one	O
list	O
,	O
ability	O
to	O
file	O
emails	O
into	O
folders	O
,	O
ability	O
to	O
search	O
for	O
emails	O
,	O
and	O
ability	O
to	O
automatically	O
append	O
signatures	O
to	O
outgoing	O
emails	O
.	O
</s>
<s>
It	O
also	O
integrates	O
with	O
the	O
Contacts	O
list	O
,	O
Calendar	B-Operating_System
,	O
Maps	O
and	O
other	O
apps	O
.	O
</s>
<s>
Apple	B-Operating_System
Mail	I-Operating_System
was	O
originally	O
developed	O
by	O
NeXT	O
as	O
NeXTMail	O
,	O
the	O
email	O
application	O
for	O
its	O
NeXTSTEP	B-Application
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
It	O
supported	O
rich	O
text	O
formatting	O
with	O
images	O
and	O
voice	O
messaging	O
,	O
and	O
MIME	B-Protocol
emails	O
.	O
</s>
<s>
It	O
also	O
supported	O
a	O
text-based	B-Application
user	I-Application
interface	I-Application
(	O
TUI	B-Application
)	O
to	O
allow	O
for	O
backwards	O
compatibility	O
.	O
</s>
<s>
When	O
Apple	O
began	O
to	O
adapt	O
NeXTSTEP	B-Application
to	O
become	O
Mac	B-Device
OS	I-Device
X	I-Device
,	O
both	O
the	O
operating	B-General_Concept
system	I-General_Concept
and	O
the	O
application	O
went	O
through	O
various	O
stages	O
as	O
it	O
was	O
developed	O
.	O
</s>
<s>
In	O
a	O
beta	O
version	O
(	O
codenamed	O
"	O
Rhapsody	B-Operating_System
"	O
)	O
and	O
various	O
other	O
early	O
pre-releases	O
of	O
Mac	B-Device
OS	I-Device
X	I-Device
,	O
Mail	O
was	O
known	O
as	O
MailViewer	O
.	O
</s>
<s>
However	O
,	O
with	O
the	O
third	O
developer	O
release	O
of	O
Mac	B-Device
OS	I-Device
X	I-Device
,	O
the	O
application	O
had	O
returned	O
to	O
being	O
known	O
simply	O
as	O
Mail	O
.	O
</s>
<s>
Apple	B-Operating_System
Mail	I-Operating_System
was	O
included	O
in	O
all	O
versions	O
of	O
macOS	B-Application
up	O
to	O
and	O
including	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
Panther	I-Operating_System
,	O
which	O
was	O
released	O
on	O
October	O
24	O
,	O
2003	O
.	O
</s>
<s>
It	O
was	O
integrated	O
with	O
other	O
Apple	O
applications	O
such	O
as	O
Address	B-Operating_System
Book	I-Operating_System
,	O
iChat	B-Protocol
,	O
and	O
iCal	B-Operating_System
.	O
</s>
<s>
In	O
Mac	B-Application
OS	I-Application
X	I-Application
Tiger	I-Application
(	O
version	O
10.4	B-Application
)	O
,	O
Mail	O
version	O
2	O
included	O
a	O
proprietary	B-Application
single-message-per-file	O
format	O
(	O
with	O
the	O
filename	O
extension	O
.emlx	B-Operating_System
)	O
to	O
permit	O
indexing	O
by	O
Spotlight	B-Application
.	O
</s>
<s>
"	O
Smart	O
mailboxes	O
"	O
that	O
used	O
Spotlight	B-Application
technology	I-Application
to	O
sort	O
mail	O
into	O
folders	O
.	O
</s>
<s>
HTML	B-Language
message	O
composition	O
.	O
</s>
<s>
According	O
to	O
many	O
users	O
,	O
and	O
even	O
Apple	O
's	O
own	O
human	B-Application
interface	I-Application
guidelines	I-Application
at	O
the	O
time	O
,	O
this	O
was	O
worse	O
for	O
usability	O
.	O
</s>
<s>
In	O
Mac	B-Application
OS	I-Application
X	I-Application
Leopard	I-Application
(	O
version	O
10.5	O
)	O
,	O
Mail	O
version	O
3	O
included	O
personalized	O
stationery	O
,	O
handled	O
in	O
standard	O
HTML	B-Language
format	O
.	O
</s>
<s>
In	O
addition	O
,	O
it	O
offered	O
notes	B-Operating_System
and	O
to-dos	O
(	O
which	O
could	O
be	O
synced	O
with	O
iCal	B-Operating_System
)	O
as	O
well	O
as	O
a	O
built-in	O
RSS	O
reader	O
.	O
</s>
<s>
It	O
also	O
introduced	O
IMAP	B-Protocol
IDLE	I-Protocol
support	O
for	O
account	O
inboxes	O
.	O
</s>
<s>
Mac	B-Device
OS	I-Device
X	I-Device
Snow	I-Device
Leopard	I-Device
(	O
version	O
10.6	B-Device
)	O
brought	O
Microsoft	B-Operating_System
Exchange	I-Operating_System
Server	I-Operating_System
2007	O
support	O
.	O
</s>
<s>
In	O
Mac	B-Application
OS	I-Application
X	I-Application
Lion	I-Application
(	O
version	O
10.7	B-Application
)	O
,	O
Mail	O
featured	O
a	O
redesigned	O
iPad-like	O
user	O
interface	O
with	O
full-screen	O
capabilities	O
,	O
an	O
updated	O
message	O
search	O
interface	O
,	O
support	O
for	O
Microsoft	B-Operating_System
Exchange	I-Operating_System
Server	I-Operating_System
2010	O
and	O
Yahoo	O
!	O
</s>
<s>
Mail	O
(	O
via	O
IMAP	B-Protocol
)	O
.	O
</s>
<s>
Also	O
added	O
was	O
the	O
capability	O
to	O
group	O
messages	O
by	O
subject	O
in	O
a	O
similar	O
fashion	O
to	O
Mail	O
on	O
iOS	B-Operating_System
4	I-Operating_System
.	O
</s>
<s>
The	O
bounce	O
function	O
,	O
where	O
unwanted	O
emails	O
could	O
be	O
bounced	O
back	O
to	O
the	O
sender	O
,	O
was	O
dropped	O
,	O
as	O
was	O
support	O
for	O
Exchange	B-Operating_System
push	O
email	O
.	O
</s>
<s>
In	O
OS	B-Operating_System
X	I-Operating_System
Mountain	I-Operating_System
Lion	I-Operating_System
(	O
version	O
10.8	B-Operating_System
)	O
,	O
Mail	O
received	O
VIP	O
tagging	O
,	O
Safari-style	O
inline	O
search	O
for	O
words	O
within	O
an	O
email	O
message	O
,	O
the	O
ability	O
to	O
sync	O
with	O
iCloud	B-Application
and	O
new	O
sharing	O
features	O
.	O
</s>
<s>
Notes	B-Operating_System
was	O
split	O
off	O
into	O
a	O
stand-alone	O
application	O
.	O
</s>
<s>
In	O
OS	B-Operating_System
X	I-Operating_System
Mavericks	I-Operating_System
(	O
version	O
10.9	O
)	O
,	O
Mail	O
ceased	O
support	O
for	O
plain-text	O
MIME	B-Protocol
multipart/alternative	O
messages	O
and	O
solely	O
retained	O
the	O
HTML	B-Language
or	O
rich-text	O
version	O
.	O
</s>
<s>
In	O
OS	B-Device
X	I-Device
Yosemite	I-Device
(	O
version	O
10.10	O
)	O
,	O
Mail	O
introduced	O
Markup	O
(	O
inline	O
annotation	O
of	O
PDF	O
or	O
image	O
files	O
)	O
and	O
Mail	O
Drop	O
(	O
automatically	O
uploads	O
attachments	O
to	O
iCloud	B-Application
,	O
and	O
sends	O
a	O
link	O
in	O
the	O
message	O
instead	O
of	O
the	O
whole	O
file	O
)	O
.	O
</s>
<s>
In	O
OS	B-Operating_System
X	I-Operating_System
El	I-Operating_System
Capitan	I-Operating_System
(	O
version	O
10.11	O
)	O
,	O
a	O
filter	O
was	O
added	O
to	O
the	O
message	O
list	O
to	O
filter	O
by	O
various	O
options	O
such	O
as	O
Unread	O
,	O
Flagged	O
,	O
or	O
messages	O
with	O
attachments	O
.	O
</s>
<s>
Streaming	O
notification	O
support	O
for	O
Exchange	B-Operating_System
accounts	O
was	O
also	O
added	O
.	O
</s>
<s>
In	O
macOS	B-Operating_System
10.13	I-Operating_System
(	O
High	B-Operating_System
Sierra	I-Operating_System
)	O
Mail	O
reached	O
version	O
11.5	O
,	O
a	O
version	O
that	O
was	O
not	O
further	O
upgraded	O
(	O
in	O
High	B-Operating_System
Sierra	I-Operating_System
,	O
at	O
least	O
until	O
2021	O
)	O
.	O
</s>
<s>
Support	O
for	O
macOS	B-Application
's	O
new	O
"	O
dark	B-General_Concept
mode	I-General_Concept
"	O
was	O
added	O
to	O
Mail	O
.	O
</s>
<s>
In	O
macOS	B-Operating_System
Big	I-Operating_System
Sur	I-Operating_System
,	O
Mail	O
was	O
updated	O
alongside	O
the	O
other	O
first-party	O
apps	O
to	O
feature	O
the	O
new	O
design	O
language	O
of	O
Big	B-Operating_System
Sur	I-Operating_System
,	O
with	O
a	O
full-height	O
sidebar	O
and	O
updated	O
icons	O
that	O
match	O
the	O
blue	O
color	O
of	O
the	O
app	O
's	O
icon	O
.	O
</s>
<s>
The	O
Mail	O
app	O
icon	O
was	O
changed	O
to	O
be	O
more	O
consistent	O
with	O
the	O
iOS	B-Application
version	O
,	O
depicting	O
a	O
white	O
envelope	O
on	O
a	O
blue	O
background	O
,	O
albeit	O
with	O
a	O
more	O
"	O
3D	O
"	O
look	O
that	O
has	O
the	O
text	O
"	O
Apple	O
Park	O
California	O
95014	O
"	O
subtly	O
etched	O
on	O
the	O
envelope	O
.	O
</s>
<s>
Extensions	O
from	O
the	O
Mac	O
App	O
Store	O
can	O
now	O
integrate	O
with	O
the	O
Mail	O
app	O
,	O
and	O
iCloud+	O
subscribers	O
can	O
easily	O
create	O
a	O
new	O
email	O
address	O
that	O
forwards	O
to	O
their	O
primary	O
address	O
.	O
</s>
