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.\"	@(#)mail.1	8.8 (Berkeley) 4/28/95
.\"
.Dd $Mdocdate: March 8 2021 $
.Dt MAIL 1
.Os
.Sh NAME
.Nm mail ,
.Nm mailx ,
.Nm Mail
.Nd send and receive mail
.Sh SYNOPSIS
.Nm mail
.Bk -words
.Op Fl dEIinv
.Op Fl b Ar list
.Op Fl c Ar list
.Op Fl r Ar from-addr
.Op Fl s Ar subject
.Ar to-addr ...
.Ek
.Nm mail
.Op Fl dEIiNnv
.Fl f
.Op Ar file
.Nm mail
.Op Fl dEIiNnv
.Op Fl u Ar user
.Sh DESCRIPTION
.Nm mail
is an intelligent mail processing system which has
a command syntax reminiscent of
.Xr ed 1
with lines replaced by messages.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl b Ar list
Send blind carbon copies to
.Ar list .
.It Fl c Ar list
Send carbon copies to
.Ar list
of users.
.Ar list
should be a comma separated list of names.
.It Fl d
Causes
.Nm mail
to output all sorts of information useful for debugging
.Nm mail .
.It Fl E
Don't send messages with an empty body.
.It Fl f
Use an alternate mailbox.
Defaults to the user's
.Ar mbox
if no
.Ar file
is specified.
When quit,
.Nm mail
writes undeleted messages back to this
.Ar file .
.It Fl I
Forces
.Nm mail
to run in interactive mode, even when input is not a terminal.
In particular, the special
.Ic ~
command character, used when sending mail, is only available interactively.
.It Fl i
Ignore tty interrupt signals.
This is
particularly useful when using
.Nm mail
on noisy phone lines.
.It Fl N
Inhibits initial display of message headers
when reading mail or editing a mail folder.
.It Fl n
Inhibits reading
.Pa /etc/mail.rc
upon startup.
.It Fl r Ar from-addr
Use
.Ar from-addr
as the from address in the message and envelope.
Overrides any
.Ar from
options in the startup files.
.It Fl s Ar subject
Specify subject on command line
(only the first argument after the
.Fl s
flag is used as a subject; be careful to quote subjects
containing spaces).
.It Fl u Ar user
Equivalent to:
.Pp
.Dl $ mail -f /var/mail/user
.Pp
except that locking is done.
.It Fl v
Verbose mode.
The details of
delivery are displayed on the user's terminal.
.El
.Ss Startup actions
At startup time,
.Nm mail
will execute commands in the system command file,
.Pa /etc/mail.rc ,
unless explicitly told not to by using the
.Fl n
option.
Next, the commands in the user's personal command file
.Pa ~/.mailrc
are executed.
.Nm mail
then examines its command line options to determine whether the user
requested a new message to be sent or existing messages in a mailbox
to be examined.
.Ss Sending mail
To send a message to one or more people,
.Nm mail
can be invoked with arguments which are the names of people to
whom the mail will be sent.
You are then expected to type in
your message, followed
by a control-D
.Pq Sq ^D
at the beginning of a line.
The section below,
.Sx Replying to or originating mail ,
describes some features of
.Nm mail
available to help you compose your letter.
.Ss Reading mail
In normal usage,
.Nm mail
is given no arguments and checks your mail out of the
post office, then
prints out a one line header of each message found.
The current message is initially set to the first message (numbered 1)
and can be printed using the
.Ic print
command (which can be abbreviated
.Ic p ) .
Moving among the messages is much like moving between lines in
.Xr ed 1 ;
you may use
.Ic +
and
.Ic -
to shift forwards and backwards, or simply enter a message number to move
directly.
.Ss Disposing of mail
After examining a message you can
.Ic delete
.Pq Ic d
or
.Ic reply
.Pq Ic r
to it.
Deletion causes the
.Nm mail
program to forget about the message.
This is not irreversible; the message can be
.Ic undeleted
.Pq Ic u
by giving its number, or the
.Nm mail
session can be aborted by giving the
.Ic exit
.Pq Ic x
command.
Deleted messages, however, will usually disappear, never to be seen again.
.Ss Specifying messages
Commands such as
.Ic print
and
.Ic delete
can be given a list of message numbers as arguments to apply
to a number of messages at once.
Thus
.Ic delete 1 2
deletes messages 1 and 2, while
.Ic delete 1\-5
deletes messages 1 through 5.
.Pp
Messages may also be selected using one of the following categories:
.Pp
.Bl -tag -width Ds -offset indent -compact
.It *
all messages
.It $
last message
.It :d
deleted messages
.It :n
new messages
.It :o
old messages
.It :r
read messages
.It :u
unread messages
.El
.Pp
Thus the command
.Ic top ,
which prints the first few lines of a message,
could be used in
.Ic top *
to print the first few lines of all messages.
.Ss Replying to or originating mail
You can use the
.Ic reply
command to
set up a response to a message, sending it back to the
person who it was from.
Text you then type in, up to an end-of-file,
defines the contents of the message.
While you are composing a message,
.Nm mail
treats lines beginning with the tilde
.Pq Sq ~
character specially.
For instance, typing
.Ic ~m
(alone on a line) will place a copy
of the current message into the response, right shifting it by a single
tab-stop (see the
.Va indentprefix
variable, below).
Other escapes will set up subject fields, add and delete recipients
to the message, and allow you to escape to an editor to revise the
message or to a shell to run some commands.
(These options
are given in the summary below.)
.Ss Ending a mail processing session
You can end a
.Nm mail
session with the
.Ic quit
.Pq Ic q
command.
Messages which have been examined go to your
.Ar mbox
file unless they have been deleted, in which case they are discarded.
Unexamined messages go back to the post office (see the
.Fl f
option above).
.Ss Personal and system wide distribution lists
It is also possible to create personal distribution lists so that,
for instance, you can send mail to
.Dq Li cohorts
and have it go
to a group of people.
Such lists can be defined by placing a line like
.Pp
.Dl alias cohorts bill ozalp jkf mark kridle@ucbcory
.Pp
in the file
.Pa .mailrc
in your home directory.
The current list of such aliases can be displayed with the
.Ic alias
command in
.Nm mail .
System wide distribution lists can be created by editing
.Pa /etc/mail/aliases
(see
.Xr aliases 5 ) ;
these are kept in a different syntax.
In mail you send, personal aliases will be expanded in mail sent
to others so that they will be able to
.Ic reply
to the recipients.
System wide aliases
are not expanded when the mail is sent,
but any reply returned to the machine will have the system wide
alias expanded as all mail goes through an MTA.
.Ss Recipient address specifications
Recipient addresses (any of the
.Dq To ,
.Dq Cc
or
.Dq Bcc
header fields) are subject to expansion when the
.Ic expandaddr
option is set.
.Pp
An address may be expanded as follows:
.Bl -bullet -width Ds
.It
An address that starts with a pipe
.Pq Ql |
character is treated as a command to run.
The command immediately following the
.Ql |
is executed with the message as its standard input.
.It
An address that starts with a
.Ql +
character is treated as a folder.
.It
An address that contains a
.Ql /
character but no
.Ql \&! ,
.Ql % ,
or
.Ql @
characters is also treated as a folder.
.It
If none of the above apply, the recipient is treated as
a local or network mail address.
.El
.Pp
If the
.Ic expandaddr
option is not set (the default), no expansion is performed and
the recipient is treated as a local or network mail address.
.Sh SUMMARY
(Adapted from the
.Dq Mail Reference Manual . )
.Pp
Each command is typed on a line by itself, and may take arguments
following the command word.
The command need not be typed in its
entirety \(em the first command which matches the typed prefix is used.
For commands which take message lists as arguments, if no message
list is given, then the next message forward which satisfies the
command's requirements is used.
If there are no messages forward of
the current message, the search proceeds backwards, and if there are no
good messages at all,
.Nm mail
types
.Dq \&No applicable messages
and
aborts the command.
.Bl -tag -width delete
.It Ic -
Print out the preceding message.
If given a numeric
argument
.Ar n ,
goes to the
.Ar n Ns th
previous message and prints it.
.It Ic \&=
Prints the currently selected message number.
.It Ic \&?
Prints a brief summary of commands.
.It Ic \&!
Executes the shell
(see
.Xr sh 1
and
.Xr csh 1 )
command which follows.
.It Ic alias
.Pq Ic a
With no arguments, prints out all currently defined aliases.
With one
argument, prints out that alias.
With more than one argument, creates
a new alias or changes an old one.
.It Ic alternates
.Pq Ic alt
The
.Ic alternates
command is useful if you have accounts on several machines.
It can be used to inform
.Nm mail
that the listed addresses are really you.
When you
.Ic reply
to messages,
.Nm mail
will not send a copy of the message to any of the addresses
listed on the
.Ic alternates
list.
If the
.Ic alternates
command is given with no argument, the current set of alternate
names is displayed.
.It Ic chdir
.Pf ( Ic cd
or
.Ic ch )
Changes the user's working directory to that specified, if given.
If
no directory is given, then changes to the user's login directory.
.It Ic copy
.Pq Ic c
The
.Ic copy
command does the same thing that
.Ic save
does, except that it does not mark the messages it
is used on for deletion when you quit.
.It Ic delete
.Pq Ic d
Takes a list of messages as argument and marks them all as deleted.
Deleted messages will not be saved in
.Ar mbox ,
nor will they be available for most other commands.
.It Ic dp
(also
.Ic dt )
Deletes the current message and prints the next message.
If there is no next message,
.Nm mail
says
.Dq Li "\&No more messages."
.It Ic edit
.Pq Ic e
Takes a list of messages and points the text editor at each one in
turn.
On return from the editor, the message is read back in.
.It Ic exit
.Pf ( Ic ex
or
.Ic x )
Effects an immediate return to the shell without
modifying the user's system mailbox, his
.Ar mbox
file, or his edit file in
.Fl f .
.It Ic file
.Pq Ic fi
The same as
.Ic folder .
.It Ic folder
.Pq Ic fo
The
.Ic folder
command switches to a new mail file or folder.
With no
arguments, it tells you which file you are currently reading.
If you give it an argument, it will write out changes (such
as deletions) you have made in the current file and read in
the new file.
Some special conventions are recognized for
the name.
# means the previous file, % means your system
mailbox, %user means user's system mailbox, & means
your
.Ar mbox
file, and
+folder means a file in your folder
directory.
.It Ic folders
List the names of the folders in your folder directory.
.It Ic from
.Pq Ic f
Takes a list of messages and prints their message headers.
.It Ic headers
.Pq Ic h
Lists the current windowful of headers.
To view the next or previous group of headers, see the
.Ic z
command.
.It Ic help
A synonym for
.Ic \&? .
.It Ic hold
.Pf ( Ic ho ,
also
.Ic preserve )
Takes a message list and marks each
message therein to be saved in the
user's system mailbox instead of in
.Ar mbox .
Does not override the
.Ic delete
command.
.It Ic ignore
Add the list of header fields named to the
.Ar ignored list .
Header fields in the ignore list are not printed
on your terminal when you print a message.
This
command is very handy for suppression of certain machine-generated
header fields.
The
.Ic Type
and
.Ic Print
commands can be used to print a message in its entirety, including
ignored fields.
If
.Ic ignore
is executed with no arguments, it lists the current set of
ignored fields.
.It Ic inc
Incorporate any new messages that have arrived while mail
is being read.
The new messages are added to the end of the message list,
and the current message is reset to be the first new mail message.
This does not renumber the existing message list, nor
does it cause any changes made so far to be saved.
.It Ic list
.Pq Ic l
List the valid
.Nm
commands.
.It Ic mail
.Pq Ic m
Takes as argument login names and distribution group names and sends
mail to those people.
.It Ic mbox
Indicate that a list of messages be sent to
.Ar mbox
in your home directory when you quit.
This is the default
action for messages if you do
.Em not
have the
.Ic hold
option set.
.It Ic more
.Pq Ic \&mo
Takes a message list and invokes the pager on that list.
.It Ic next
.Pq Ic n
(like
.Ic +
or CR)
Goes to the next message in sequence and types it.
With an argument list, types the next matching message.
.It Ic preserve
.Pq Ic pre
A synonym for
.Ic hold .
.It Ic Print
.Pq Ic P
Like
.Ic print
but also prints out ignored header fields.
See also
.Ic print ,
.Ic ignore ,
and
.Ic retain .
.It Ic print
.Pq Ic p
Takes a message list and types out each message on the user's terminal.
.It Ic quit
.Pq Ic q
Terminates the session, saving all undeleted, unsaved messages in
the user's
.Ar mbox
file in his login directory, preserving all messages marked with
.Ic hold
or
.Ic preserve
or never referenced
in his system mailbox, and removing all other messages from his system
mailbox.
If new mail has arrived during the session, the message
.Dq Li "You have new mail"
is given.
If given while editing a
mailbox file with the
.Fl f
flag, then the edit file is rewritten.
A return to the shell is
effected, unless the rewrite of edit file fails, in which case the user
can escape with the
.Ic exit
command.
.It Ic Reply
.Pq Ic R
Reply to originator.
Does not reply to other
recipients of the original message.
.It Ic reply
.Pq Ic r
Takes a message list and sends mail to the sender and all
recipients of the specified message.
The default message must not be deleted.
.It Ic respond
A synonym for
.Ic reply .
.It Ic retain
Add the list of header fields named to the
.Ar retained list .
Only the header fields in the retain list
are shown on your terminal when you print a message.
All other header fields are suppressed.
The
.Ic Type
and
.Ic Print
commands can be used to print a message in its entirety.
If
.Ic retain
is executed with no arguments, it lists the current set of
retained fields.
.It Ic save
.Pq Ic s
Takes a message list and a filename and appends each message in
turn to the end of the file.
The filename in quotes, followed by the line
count and character count is echoed on the user's terminal.
.It Ic saveignore
.Ic saveignore
is to
.Ic save
what
.Ic ignore
is to
.Ic print
and
.Ic type .
Header fields thus marked are filtered out when
saving a message by
.Ic save
or when automatically saving to
.Ar mbox .
.It Ic saveretain
.Ic saveretain
is to
.Ic save
what
.Ic retain
is to
.Ic print
and
.Ic type .
Header fields thus marked are the only ones saved
with a message when saving by
.Ic save
or when automatically saving to
.Ar mbox .
.Ic saveretain
overrides
.Ic saveignore .
.It Ic set
.Pq Ic se
With no arguments, prints all variable values.
Otherwise, sets
option.
Arguments are of the form
.Ar option=value
(no space before or after =) or
.Ar option .
Quotation marks may be placed around any part of the assignment statement to
quote blanks or tabs, i.e.,
.Ic set indentprefix="->" .
.It Ic shell
.Pq Ic sh
Invokes an interactive version of the shell.
.It Ic size
Takes a message list and prints out the size in characters of each
message.
.It Ic source
The
.Ic source
command reads
commands from a file.
.It Ic top
Takes a message list and prints the top few lines of each.
The number of
lines printed is controlled by the variable
.Ic toplines
and defaults to five.
.It Ic Type
.Pq Ic T
Identical to the
.Ic Print
command.
.It Ic type
.Pq Ic t
A synonym for
.Ic print .
.It Ic unalias
Takes a list of names defined by
.Ic alias
commands and discards the remembered groups of users.
The group names
no longer have any significance.
.It Ic undelete
.Pq Ic u
Takes a message list and marks each message as not being deleted.
.It Ic unread
.Pq Ic U
Takes a message list and marks each message as not having been read.
.It Ic unset
Takes a list of option names and discards their remembered values;
the inverse of
.Ic set .
.It Ic visual
.Pq Ic v
Takes a message list and invokes the display editor on each message.
.It Ic write
.Pq Ic w
Similar to
.Ic save ,
except that
.Ic only
the message body
(without the header)
is saved.
Extremely useful for such tasks as sending and receiving source
program text over the message system.
.It Ic xit
.Pq Ic x
A synonym for
.Ic exit .
.It Ic z
.Nm mail
presents message headers in windowfuls as described under the
.Ic headers
command.
You can move
.Nm mail Ns 's
attention forward to the next window with the
.Ic z
command.
Also, you can move to the previous window by using
.Ic z- .
.El
.Ss Tilde/escapes
Here is a summary of the tilde escapes,
which are used when composing messages to perform
special functions.
Tilde escapes are only recognized at the beginning
of lines.
The name
.Dq tilde escape
is somewhat of a misnomer since the actual escape character can be set
by the option
.Ic escape .
.Pp
.Bl -tag -width Ds -compact
.It Ic ~b Ns Ar name ...
Add the given names to the list of carbon copy recipients but do not make
the names visible in the Cc: line ("blind" carbon copy).
.Pp
.It Ic ~c Ns Ar name ...
Add the given names to the list of carbon copy recipients.
.Pp
.It Ic ~d
Read the file
.Pa dead.letter
from your home directory into the message.
.Pp
.It Ic ~e
Invoke the text editor on the message collected so far.
After the
editing session is finished, you may continue appending text to the
message.
.Pp
.It Ic ~F Ns Ar messages
Identical to
.Ic ~f ,
except all message headers are included.
.Pp
.It Ic ~f Ns Ar messages
Read the named messages into the message being sent.
If no messages are specified, read in the current message.
Message headers currently being ignored (by the
.Ic ignore
or
.Ic retain
command) are not included.
.Pp
.It Ic ~h
Edit the message header fields by typing each one in turn and allowing
the user to append text to the end or modify the field by using the
current terminal erase and kill characters.
.Pp
.It Ic ~M Ns Ar messages
Identical to
.Ic ~m ,
except all message headers are included.
.Pp
.It Ic ~m Ns Ar messages
Read the named messages into the message being sent, indented by a
tab or by the value of
.Va indentprefix .
If no messages are specified,
read the current message.
Message headers currently being ignored (by the
.Ic ignore
or
.Ic retain
command) are not included.
.Pp
.It Ic ~p
Print out the message collected so far, prefaced by the message header
fields.
.Pp
.It Ic ~q
Abort the message being sent, copying the message to
.Pa dead.letter
in your home directory if
.Ic save
is set.
.Pp
.It Ic ~r Ns Ar filename
.It Ic ~< Ns Ar filename
Read the named file into the message.
.Pp
.It Ic ~s Ns Ar string
Cause the named string to become the current subject field.
.Pp
.It Ic ~t Ns Ar name ...
Add the given names to the direct recipient list.
.Pp
.It Ic ~v
Invoke an alternate editor (defined by the
.Ev VISUAL
option) on the
message collected so far.
Usually, the alternate editor will be a
screen editor.
After you quit the editor, you may resume appending
text to the end of your message.
.Pp
.It Ic ~w Ns Ar filename
Write the message onto the named file.
.Pp
.It Ic ~x
Abort the message being sent.
No message is copied to
.Pa ~/dead.letter ,
even if
.Ic save
is set.
.Pp
.It Ic ~?
Prints a brief summary of tilde escapes.
.Pp
.It Ic ~! Ns Ar command
Execute the indicated shell command, then return to the message.
.Pp
.It Ic ~| Ns Ar command
Pipe the message through the command as a filter.
If the command gives
no output or terminates abnormally, retain the original text of the
message.
The command
.Xr fmt 1
is often used as
.Ic command
to rejustify the message.
.Pp
.It Ic ~: Ns Ar mail-command
.It Ic ~_ Ns Ar mail-command
Execute the given mail command.
Not all commands, however, are allowed.
.Pp
.It Ic ~~ Ns Ar string
Insert the string of text in the message prefaced by a single ~.
If
you have changed the escape character, then you should double
that character in order to send it.
.Pp
.It Ic ~.
Simulate end of file on input.
.El
.Ss Mail options
A number of options can be set in the
.Pa .mailrc
file to alter the behavior of
.Nm ,
controlled via the
.Ic set
and
.Ic unset
commands.
Options may be either binary, in which case it is only
significant to see whether they are set or not; or string, in which
case the actual value is of interest.
The binary options include the following:
.Bl -tag -width append
.It Ar append
Causes messages saved in
.Ar mbox
to be appended to the end rather than prepended.
This should always be set (perhaps in
.Pa /etc/mail.rc ) .
.It Ar ask , asksub
Causes
.Nm mail
to prompt you for the subject of each message you send.
If
you respond with simply a newline, no subject field will be sent.
.It Ar askbcc
Causes you to be prompted for additional blind carbon copy recipients at the
end of each message.
Responding with a newline indicates your
satisfaction with the current list.
.It Ar askcc
Causes you to be prompted for additional carbon copy recipients at the
end of each message.
Responding with a newline indicates your
satisfaction with the current list.
.It Ar autoinc
Causes new mail to be automatically incorporated when it arrives.
Setting this is similar to issuing the
.Ic inc
command at each prompt, except that the current message is not
reset when new mail arrives.
.It Ar autoprint
Causes the
.Ic delete
command to behave like
.Ic dp ;
thus, after deleting a message, the next one will be typed
automatically.
.It Ar debug
Setting the binary option
.Ar debug
is the same as specifying
.Fl d
on the command line and causes
.Nm mail
to output all sorts of information useful for debugging
.Nm mail .
.It Ar dot
The binary option
.Ar dot
causes
.Nm mail
to interpret a period alone on a line as the terminator
of a message you are sending.
.It Ar expandaddr
Causes
.Nm mail
to expand message recipient addresses, as explained in the section
.Sx Recipient address specifications .
.It Ar from
Causes
.Nm mail
to use the specified sender address in the
.Dq From:
field of the message header.
A stripped down version of the address is also used in the message envelope.
If unset, the message will not include an explicit sender address and
a default value will be added by the MTA, typically
.Dq user@host .
This value can be overridden by specifying the
.Fl r
flag on the command line.
.It Ar hold
This option is used to hold messages in the system mailbox
by default.
.It Ar ignore
Causes interrupt signals from your terminal to be ignored and echoed as
@'s.
.It Ar ignoreeof
An option related to
.Ar dot
is
.Ar ignoreeof
which makes
.Nm mail
refuse to accept a control-D as the end of a message.
.Ar ignoreeof
also applies to
.Nm mail
command mode.
.It Ar keep
Setting this option causes
.Nm
to truncate your system mailbox instead of deleting it
when it's empty.
.It Ar keepsave
Messages saved with the
.Ic save
command are not normally saved in
.Ar mbox
at quit time.
Use this option to retain those messages.
.It Ar metoo
Usually, when a group is expanded that contains the sender, the sender
is removed from the expansion.
Setting this option causes the sender
to be included in the group.
.It Ar noheader
Setting the option
.Ar noheader
is the same as giving the
.Fl N
flag on the command line.
.It Ar nosave
Normally, when you abort a message with two interrupt characters
(usually control-C),
.Nm mail
copies the partial letter to the file
.Pa dead.letter
in your home directory.
Setting the binary option
.Ar nosave
prevents this.
.It Ar quiet
Suppresses the printing of the version when first invoked.
.It Ar Replyall
Reverses the sense of
.Ic reply
and
.Ic Reply
commands.
.It Ar searchheaders
If this option is set, then a message-list specifier in the form
.Dq /x:y
will expand to all messages containing the substring
.Sq y
in the header
field
.Sq x .
The string search is case insensitive.
If
.Sq x
is omitted, it will default to the
.Dq Subject
header field.
The form
.Dq /to:y
is a special case, and will expand
to all messages containing the substring
.Sq y
in the
.Dq To ,
.Dq Cc
or
.Dq Bcc
header fields.
The check for
.Dq to
is case sensitive, so that
.Dq /To:y
can be used to limit the search for
.Sq y
to just the
.Dq To:
field.
.It Ar skipempty
Don't send messages with an empty body.
.It Ar verbose
Setting the option
.Ar verbose
is the same as using the
.Fl v
flag on the command line.
When
.Nm
runs in verbose mode,
the actual delivery of messages is displayed on the user's
terminal.
.El
.Ss Option string values
.Bl -tag -width Va
.It Ev EDITOR
Pathname of the text editor to use in the
.Ic edit
command and
.Ic ~e
escape.
If not defined,
.Pa /usr/bin/ex
is used.
.It Ev LISTER
Pathname of the directory lister to use in the
.Ic folders
command.
Default is
.Pa /bin/ls .
.It Ev MBOX
The name of the
.Ar mbox
file.
It can be the name of a folder.
The default is
.Dq Li mbox
in the user's home directory.
.It Ev PAGER
Pathname of the program to use in the
.Ic more
command or when the
.Ar crt
variable is set.
The default paginator
.Xr more 1
is used if this option is not defined.
.It Ev SHELL
Pathname of the shell to use in the
.Ic !\&
command and the
.Ic ~!\&
escape.
A default shell is used if this option is
not defined.
.It Ev VISUAL
Pathname of the text editor to use in the
.Ic visual
command and
.Ic ~v
escape.
If not defined,
.Pa /usr/bin/vi
is used.
.It Ar crt
The valued option
.Ar crt
is used as a threshold to determine how long a message must
be before
.Ev PAGER
is used to read it.
If
.Ar crt
is set without a value,
then the height of the terminal screen stored in the system
is used to compute the threshold (see
.Xr stty 1 ) .
.It Ar escape
If defined, the first character of this option gives the character to
use in the place of ~ to denote escapes.
.It Ar folder
The name of the directory to use for storing folders of
messages.
If this name begins with a
.Ql / ,
.Nm mail
considers it to be an absolute pathname; otherwise, the
folder directory is found relative to your home directory.
.It Ar indentprefix
String used by the
.Ic ~m
tilde escape for indenting messages, in place of the normal tab character
.Pq Sq ^I .
Be sure to quote the value if it contains
spaces or tabs.
.It Ar record
If defined, gives the pathname of the file used to record all outgoing
mail.
If not defined, then outgoing mail is not so saved.
.It Ar screen
Size of window of message headers for
.Ic z .
.It Ar sendmail
Pathname to an alternative mail delivery system.
.It Ar toplines
If defined, gives the number of lines of a message to be printed out
with the
.Ic top
command; normally, the first five lines are printed.
.El
.Sh ENVIRONMENT
.Nm mail
utilizes the
.Ev HOME ,
.Ev LOGNAME ,
.Ev MAIL ,
.Ev MAILRC ,
and
.Ev USER
environment variables.
.Pp
If the
.Ev MAIL
environment variable is set, its value is used as the path to the
user's mail spool.
.Sh FILES
.Bl -tag -width /usr/share/misc/mail.*help -compact
.It Pa /var/mail/*
post office (unless overridden by the
.Ev MAIL
environment variable)
.It Pa ~/mbox
user's old mail
.It Pa ~/.mailrc
file giving initial mail commands; can be overridden by setting the
.Ev MAILRC
environment variable
.It Pa /tmp/R*
temporary files
.It Pa /usr/share/misc/mail.*help
help files
.It Pa /etc/mail.rc
system initialization file
.El
.Sh EXIT STATUS
.Ex -std mail
.Sh SEE ALSO
.Xr fmt 1 ,
.Xr lockspool 1 ,
.Xr vacation 1 ,
.Xr aliases 5 ,
.Xr mail.local 8 ,
.Xr newaliases 8 ,
.Xr sendmail 8 ,
.Xr smtpd 8
.Rs
.\" 4.4BSD USD:7
.%A Kurt Shoens
.%T Mail Reference Manual
.%B 4.4BSD User's Supplementary Documents (USD)
.Re
.Sh STANDARDS
The
.Nm mailx
utility is compliant with the
.St -p1003.1-2008
specification.
.Pp
The flags
.Op Fl iNnu
are marked by
.St -p1003.1-2008
as being optional.
.Pp
The flags
.Op Fl eFH
are marked by
.St -p1003.1-2008
as being optional,
and are not supported by this implementation of
.Nm mailx .
.Pp
The flags
.Op Fl bcdEIrv
are extensions to the specification.
.Sh HISTORY
A
.Nm mail
command appeared in
.At v1 .
This man page is derived from the
.%T "Mail Reference Manual"
originally written by Kurt Shoens.
.Sh BUGS
Usually,
.Nm mail
and
.Nm mailx
are just links to
.Nm Mail ,
which can be confusing.