NAIL(1)

NAME
nail - send and receive MIME conformant mail

SYNOPSIS
nail [ -iInv ] [ -s subject ] [ -a attachment ] [ -c cc-addr ] [ -b bcc-addr ] [ -r from-addr ] to-addr . . .

nail [ -eiInNv ] -f [ name ]

nail [ -eiInNv ] [ -u user ]

DESCRIPTION
Nail is an intelligent mail processing system, which has a command syntax reminiscent of ed(1) with lines replaced by messages. It is based on Berkeley Mail 8.1 and offers some extensions for MIME messages.

OPTIONS

-a file
    Attach the given file to the message.

-b address
    Send blind carbon copies to list. List should be a comma-separated list of names.

-c address
    Send carbon copies to list of users.

-e  Just check if mail is present in the system mailbox. If yes, return an exit status of zero, else, a non-zero value.

-f [ file ]
    Read in the contents of your mbox (or the specified file) for processing; when you quit, nail writes undeleted messages back to this file.

-i  Ignore tty interrupt signals. This is particularly useful when using nail on noisy phone lines.

-I  Forces nail to run in interactive mode even when input is not a terminal. In particular, the character when sending mail is only active in interactive mode.

-n  Inhibits reading /etc/nail.rc upon startup.

-N  Inhibits the initial display of message headers when reading mail or editing a mail folder.

-q file
    Start the message with the contents of the specified file. May be given in send mode only.

-r address
    Sets the From address. Overrides any from variable specified in environment or startup files.

-s subject
    Specify subject on command line (only the first argument after the -s flag is used as a subject; be careful to quote subjects containing spaces).

-u user
    Reads the mailbox of the given user name.

-v  Verbose mode. The details of delivery are displayed on the user's terminal.

-V  Print nail's version and exit.

USAGE

  Sending mail
To send a message to one or more people, nail 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 an 'control-D' at the beginning of a line. The section below Replying to or originating mail, describes some features of nail available to help you compose your letter.

  Reading mail
In normal usage nail 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 the first message (numbered 1) and can be printed using the print command which can be abbreviated 'p'). You can move among the messages much as you move between lines in ed(1), with the commands '+' and '-' moving backwards and forwards, and simple numbers.

  Disposing of mail
After examining a message you can delete 'd') the message or reply 'r') to it. Deletion causes the nail program to forget about the message. This is not irreversible; the message can be undeleted 'u') by giving its number, or the nail session can be aborted by giving the exit 'x') command. Deleted messages will, however, usually disappear never to be seen again.

  Specifying messages
Commands such as print and delete can be given a list of message numbers as arguments to apply to a number of messages at once. Thus 'delete 1 2' deletes messages 1 and 2, while 'delete 1-5' deletes messages 1 through 5. The special name '*' addresses all messages, and '$' addresses the last message; thus the command top which prints the first few lines of a message could be used in 'top *' to print the first few lines of all messages.

  Replying to or originating mail
You can use the 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, nail treats lines beginning with the character '~' specially. For instance, typing '~m' (alone on a line) will place a copy of the current message into the response right shifting it by a tabstop (see indentprefix variable, below). Other escapes will set up subject fields, add and delete recipients to the message, attach files to it 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.)

  Ending a mail processing session
You can end a nail session with the quit 'q') command. Messages which have been examined go to your mbox file unless they have been deleted in which case they are discarded. Unexamined messages go back to the post office. (See the -f option above).

  Personal and systemwide distribution lists
It is also possible to create a personal distribution lists so that, for instance, you can send mail to 'cohorts' and have it go to a group of people. Such lists can be defined by placing a line like
        alias cohorts bill ozalp jkf mark kridle@ucbcory
in the file .mailrc in your home directory. The current list of such aliases can be displayed with the alias command in nail. System wide distribution lists can be created by editing /etc/aliases, see aliases(5) and sendmail(8); 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 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 sendmail.

  Network mail (Internet / ARPA, UUCP, Berknet)
See mailaddr(7) for a description of network addresses. Nail has a number of options which can be set in the .mailrc file to alter its behavior; thus 'set askcc' enables the askcc feature. (These options are summarized below).

  MIME types
For any outgoing attachment, nail tries to determine the content type. It does this by reading MIME type files whose lines have the following syntax:
        type/subtype      extension [extension ...]
where type/subtype are strings describing the file contents, and extension is the part of a filename starting after the last dot. Any line not immediately beginning with an ASCII alphabetical character is ignored by nail. If there is a match with the extension of the file to attach, the given type/subtype pair is used. Otherwise, or if the filename has no extension, the content types text/plain or application/octet-stream are used, the first for text or international text files, the second for any file that contains formatting characters other than newlines and horizontal tabulators.

  MIME conformance
Nail is intended to be a MIME-conformant mail user agent, with the following exception: No special handling of "multipart/alternative" messages is performed. All parts with content types of "text" or "message" are shown. This is done because the user should see as much information as possible.

  Locale
Nail uses the LC_CTYPE locale setting to determine whether a character is printable. Thus, its value has to match the character set of the terminal nail runs on.

  Character sets
If a message contains non-ASCII characters, the character set being used must be declared within the header. Its value can be declared using the charset variable. It is normally assumed that this is the terminal character set, too. If the latter differs from the one that should be used in outgoing mail, the ttycharset variable can be used for its declaration. Any outgoing message is then converted, resulting in errors when this process cannot be done for the entire text. Attachments are never converted. Any message that is displayed on a terminal is tried to convert, too, with characters not in the terminal character set replaced by question marks.

  Commands
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 – 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, nail types 'applicable messages' and aborts the command. If the command begins with a # sign, the line is ignored.

-   Print out the preceding message. If given a numeric argument n, goes to the n'th previous message and prints it.

?   Prints a brief summary of commands.

!   Executes the shell (see sh(1) and csh(1)) command which follows.

|   A synonym for the pipe command.

Forward
    (For) Like forward, but does not add any header lines. This is not a way to hide the sender's identity, but useful for sending a message again to the same recipients.

Pipe
    (Pi) Like pipe but also pipes ignored header fields.

Print
    (P) Like print but also prints out ignored header fields. See also print, ignore and retain.

Reply
    (R) Reply to originator. Does not reply to other recipients of the original message.

Type
    (T) Identical to the Print command.

alias
    (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.

alternates
    (alt) The alternates command is useful if you have accounts on several machines. It can be used to inform nail that the listed addresses are really you. When you reply to messages, nail will not send a copy of the message to any of the addresses listed on the alternates list. If the alternates command is given with no argument, the current set of alternate names is displayed.

chdir
    (c) Changes the user's working directory to that specified, if given. If no directory is given, then changes to the user's login directory.

copy
    (co) The copy command does the same thing that save does, except that it does not mark the messages it is used on for deletion when you quit.

delete
    (d) Takes a list of messages as argument and marks them all as deleted. Deleted messages will not be saved in mbox, nor will they be available for most other commands.

dp or dt
    Deletes the current message and prints the next message. If there is no next message, nail says 'at EOF'.

edit
    (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.

else
    Marks the end of the then-part of an if statement and the beginning of the part to take effect if the condition of the if statement is false.

endif
    Marks the end of an if statement.

exit
    (ex or x) Effects an immediate return to the Shell without modifying the user's system mailbox, his mbox file, or his edit file in -f.

file
    (fi) The same as folder.

folders
    List the names of the folders in your folder directory.

folder
    (fo) The 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 mbox file, and +folder means a file in your folder directory.

forward
    (for) Takes a list of messages and a user name and sends each message to the named user.

from
    (f) Takes a list of messages and prints their message headers.

headers
    (h) Lists the current range of headers, which is an 18-message group. If a '+' argument is given, then the next 18-message group is printed, and if a '-' argument is given, the previous 18-message group is printed.

help
    A synonym for ?.

hold
    (ho, also preserve) Takes a message list and marks each message therein to be saved in the user's system mailbox instead of in mbox. Does not override the delete command.

if  Commands in nail's startup files can be executed conditionally depending on whether you are sending or receiving mail with the if command. For example, you can do:
            if receive
                    commands ...
            endif
    An else form is also available:
            if receive
                    commands ...
            else
                    commands ...
            endif
    Note that the only allowed conditions are receive and send.

ignore
    Add the list of header fields named to the 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 Type and Print commands can be used to print a message in its entirety, including ignored fields. If ignore is executed with no arguments, it lists the current set of ignored fields.

mail
    (m) Takes as argument login names and distribution group names and sends mail to those people.

mbox
    Indicate that a list of messages be sent to mbox in your home directory when you quit. This is the default action for messages if you do not have the hold option set.

next
    (n) like + or CR) Goes to the next message in sequence and types it. With an argument list, types the next matching message.

preserve
    (pre) A synonym for hold.

pipe
    (pi) Takes a message list and a shell command and pipes the messages through the command. Without an argument, the current message is piped through the command given by the cmd variable. If the page variable is set, every message is followed by a formfeed character.

print
    (p) Takes a message list and types out each message on the user's terminal. If the message is a MIME multipart message, all parts with a content type of "text" or "message" are shown, the other are hidden except for their headers.

quit
    (q) Terminates the session, saving all undeleted, unsaved messages in the user's mbox file in his login directory, preserving all messages marked with hold or 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 'You have new mail' is given. If given while editing a mailbox file with the -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 exit command.

reply or respond
    (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.

retain
    Add the list of header fields named to the 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 Type and Print commands can be used to print a message in its entirety. If retain is executed with no arguments, it lists the current set of retained fields.

save
    (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.

set (se) With no arguments, prints all variable values. Otherwise, sets option. Arguments are of the form option=value (no space before or after =) or option. Quotation marks may be placed around any part of the assignment statement to quote blanks or tabs, i.e. 'set indentprefix="->"'.

saveignore
    Saveignore is to save what ignore is to print and type. Header fields thus marked are filtered out when saving a message by save or when automatically saving to mbox. This command should only be applied to header fields that do not contain content information.

saveretain
    Saveretain is to save what retain is to print and type. Header fields thus marked are the only ones saved with a message when saving by save or when automatically saving to mbox. Saveretain overrides saveignore. The use of this command is strongly discouraged since it may strip header fields that are needed to decode the message correctly.

shell
    (sh) Invokes an interactive version of the shell.

size
    Takes a message list and prints out the size in characters of each message.

source
    The source command reads commands from a file.

top Takes a message list and prints the top few lines of each. The number of lines printed is controlled by the variable toplines and defaults to five.

type
    (t) A synonym for print.

unalias
    Takes a list of names defined by alias commands and discards the remembered groups of users. The group names no longer have any significance.

undelete
    (u) Takes a message list and marks each message as not being deleted.

unread
    (U) Takes a message list and marks each message as not having been read.

unset
    Takes a list of option names and discards their remembered values; the inverse of set.

visual
    (v) Takes a message list and invokes the display editor on each message.

write
    (w) For conventional messages, the body without all headers is written. The output is converted to its native format, if necessary. If a message is in MIME multipart format, its first part is written to the specified file, and the user is asked for a filename to save each other part. In non-interactive mode, only the parts of the multipart message that have a filename given in the part header are written, the other are discarded. The original message is never marked for deletion in the originating mail folder.

xit (x) A synonym for exit.

z   Nail presents message headers in windowfuls as described under the headers command. The z command scrolls to the next window of messages. If an argument is given, it specifies the window to use. A number prefixed by '+' or '-' indicates that the window is calculated in relation to the current position. A number without a prefix specifies an absolute window number, and a '$' lets nail scroll to the last window of messages.

  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 'tilde escape' is somewhat of a misnomer since the actual escape character can be set by the option escape.

~!command
    Execute the indicated shell command, then return to the message.

~<filename
    Identical to ~r.

~<!command
    Command is executed using the shell. Its standard output is inserted into the message.

~afilename ...
    Add the given filenames to the attachment list. If one of the files is not readable, the attachment list remains empty.

~bname ...
    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).

~cname ...
    Add the given names to the list of carbon copy recipients.

~d  Read the file 'dead.letter' from your home directory into the message.

~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.

~fmessages
    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 ignore or retain command) are not included.

~Fmessages
    Identical to ~f, except all message headers are included.

~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.

~istring
    Insert the value of the variable specified by string into the message adding a newline character at the end. If the variable is unset or empty, the message remains unaltered.

~mmessages
    Read the named messages into the message being sent, indented by a tab or by the value of indentprefix. If no messages are specified, read the current message. Message headers currently being ignored (by the ignore or retain command) are not included.

~Mmessages
    Identical to ~m, except all message headers are included.

~p  Print out the message collected so far, prefaced by the message header fields and followed by the attachment list, if any.

~q  Abort the message being sent, copying the message to "dead.letter" in your home directory if save is set.

~rfilename
    Read the named file into the message.

~sstring
    Cause the named string to become the current subject field.

~tname ...
    Add the given names to the direct recipient list.

~v  Invoke an alternate editor (defined by the 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.

~wfilename
    Write the message onto the named file.

~|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 fmt(1) is often used as command to rejustify the message.

~:nail-command
    Execute the given nail command. Not all commands, however, are allowed.

~_nail-command
    Identical to ~:.

~~string
    Insert the string of text in the message prefaced by a single ~. If you have changed the escape character, the you should double that character in order to send it.

  Variable options
Options are controlled via set and unset commands, see their entries for a syntax description. An option is also set if it is passed to nail as part of the environment, but a value given in a startup file overrides this. 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:

Replyall
    Reverses the sense of reply and Reply commands.

append
    Causes messages saved in mbox to be appended to the end rather than prepended. This should always be set.

ask or asksub
    Causes nail to prompt you for the subject of each message you send. If you respond with simply a newline, no subject field will be sent.

askattach
    If set, nail asks for files to attach at the end of each message. Responding with a newline indicates not to include an attachment.

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.

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.

autoprint
    Causes the delete command to behave like dp - thus, after deleting a message, the next one will be typed automatically.

dot The binary option dot causes nail to interpret a period alone on a line as the terminator of a message you are sending.

emptybox
    If set, an empty mailbox file is not removed. This may improve the interoperability with other MUAs when using a common folder directory.

emptystart
    If the mailbox is empty, nail normally prints 'No mail for user' and exits immediately. If this option is set, nail starts even with an empty mailbox.

hold
    This option is used to hold messages in the system mailbox by default.

ignore
    Causes interrupt signals from your terminal to be ignored and echoed as @'s.

ignoreeof
    An option related to dot is ignoreeof which makes nail refuse to accept a control-d as the end of a message. Ignoreeof also applies to nail command mode.

keep
    This option causes nail to truncate your system mailbox instead of deleting it when it is empty. This should always be set, since it prevents malicious users from creating fake mail folders in a world-writeable spool directory.

keepsave
    When you save a message, nail usually discards it from the originating folder when you quit. To retain all saved messages, set this option.

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.

noheader
    Setting the option noheader is the same as giving the -N flag on the command line.

nosave
    Normally, when you abort a message with two RUBOUT (interrupt characters) nail copies the partial letter to the file 'dead.letter' in your home directory. Setting the binary option nosave prevents this.

page
    If set, each message the pipe command prints out is followed by a formfeed character.

quiet
    Suppresses the printing of the version when first invoked.

searchheaders
    If this option is set, then a message-list specifier in the form '/x:y' will expand to all messages containing the substring 'y' in the header field 'x'. The string search is case insensitive.

stealthmua
    Inhibits the generation of the 'Message-Id:' and 'User-Agent:' header fields that include obvious references to nail. There are two pitfalls associated with this: First, the message id of outgoing messages is not known anymore. Second, an expert may still use the remaining information in the header to track down the originating mail user agent. So this option should only be set if there is a good reason to do that.

verbose
    Setting the option verbose is the same as using the -v flag on the command line. When nail runs in verbose mode, the actual delivery of messages is displayed on the user's terminal.

The string options include the following:

DEAD
    The name of the file to use for saving aborted messages. This defaults to 'dead.letter' in the user's home directory.

EDITOR
    Pathname of the text editor to use in the edit command and ~e escape. If not defined, then a default editor is used.

LISTER
    Pathname of the directory lister to use in the folders command. Default is /bin/ls.

MBOX
    The name of the mbox file. It can be the name of a folder. The default is 'mbox' in the user's home directory.

ORGANIZATION
    The value to put into the 'Organization:' field of the message header.

PAGER
    Pathname of the program to use in the more command or when crt variable is set. The default paginator more(1) is used if this option is not defined.

SHELL
    Pathname of the shell to use in the ! command and the ~! escape. A default shell is used if this option is not defined.

VISUAL
    Pathname of the text editor to use in the visual command and ~v escape.

charset
    The name of the character set used by nail. If unset, iso-8859-1 is the default. The character set of all outgoing messages that contain non-ASCII characters is declared using its value.

cmd The default value for the pipe command.

crt The valued option crt is used as a threshold to determine how long a message must be before PAGER is used to read it. If crt is set without a value, then the height of the terminal screen stored in the system is used to compute the threshold (see stty(1)).

encoding
    The default MIME encoding to use in outgoing text messages and message parts. Valid values are 8bit or quoted-printable. The default is 8bit. In case the mail transfer system is not ESMTP compliant, quoted-printable should be used instead. If there is no need to encode a message, 7bit transfer mode is used, without regard to the value of this variable. Binary data is always encoded in base64 mode.

escape
    If defined, the first character of this option gives the character to use in the place of ~ to denote escapes.

folder
    The name of the directory to use for storing folders of messages. If this name begins with a '/', nail considers it to be an absolute pathname; otherwise, the folder directory is found relative to your home directory.

from
    The address to put into the 'From:' field of the message header. If replying to a message, this address is handled as if it were in the alternates list. If this variable is set, a 'Sender:' field containing the user's name is also generated, unless the variable smtp is set and its value differs from localhost. If the machine's hostname is not valid at the Internet (for example at a dialup machine), you have to set this variable to get correct Message-ID header fields.

indentprefix
    String used by the '~m' and '~M' tilde escapes and by the quote option for indenting messages, in place of the normal tab character (^I). Be sure to quote the value if it contains spaces or tabs.

quote
    If set, nail starts a replying message with the original message prefixed by the value of the variable indentprefix. Normally, a heading consisting of 'Fromheaderfield wrote:' is printed before the quotation. If the string noheading is assigned to the quote variable, this heading is omitted. If the string headers is assigned, the headers selected by the ignore/retain commands are printed above the message body, thus quote acts like an automatic ~m command then. If the string allheaders is assigned, all headers are printed above the message body, thus quote acts like an automatic ~M command then.

screen
    When nail initially prints the message headers, it determines the number to print by looking at the speed of your terminal. The faster your terminal, the more it prints. This option overrides this calculation and specifies how many message headers you want printed. This number is also used for scrolling with the z command.

sendmail
    To use an alternate mail delivery system, set this option to the full pathname of the program to use. This should be used with care.

smtp
    Normally, nail invokes sendmail(8) directly to transfer messages. If smtp is set, a SMTP connection to the server specified by the value of this variable is used instead. If the SMTP server does not use the standard port, a value of server:port can be given, with port as a name or as a number.

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.

replyto
    The address to put into the 'Reply-To:' field of the message header. If replying to a message, this address is handled as if it were in the alternates list.

signature
    Must correspondend to the name of a readable file if set. The file's content is then appended to each singlepart message and to the first part of each multipart message. Be warned that there is no possibility to edit the signature for an individual message.

toplines
    If defined, gives the number of lines of a message to be printed out with the top command; normally, the first five lines are printed.

ttycharset
    The character set of the terminal nail operates on. There is normally no need to set this variable since nail can determine this automatically by looking at the LC_CTYPE locale setting; if this succeeds, the value is assigned at startup and will be displayed by the set command. Note that this is not necessarily a character set name that can be used in Internet messages. If unset, its default is the value of the charset variable.

ENVIRONMENT VARIABLES
Besides the variables described above, nail uses the following environment strings:

HOME
    The user's home directory.

LANG, LC_ALL, LC_CTYPE
    See locale(7).

MAIL
    Is used as the user's mailbox, if set. Otherwise, a system-dependent default is used.

MAILRC
    Is used as startup file instead of ~/.mailrc if set.

FILES

~/.mailrc
    File giving initial commands.

/etc/nail.rc
    System wide initialization file.

~/.mime.types
    Personal MIME types.

/etc/mime.types
    System wide MIME types.

SEE ALSO
fetchmail(1), fmt(1), newaliases(1), procmail(1), vacation(1), aliases(5), locale(7), mailaddr(7), sendmail(8)

NOTES

Due to limitations of nail's internal message handling, an outgoing singlepart message must always be a text message; the same applies to the first part of a multipart message. Binary files must be sent as attachments.

Nail cannot handle the binary Content-Transfer-Encoding. The base64 encoding should be used instead.

Contrasting to some versions of BSD Mail, nail is not able to act as a Mail Delivery Agent (MDA). Use procmail(1) for this purpose.

The character set conversion relies heavily on the iconv(3) function. Its functionality differs widely between the various system environments nail runs on.

HISTORY
A mail command appeared in Version 6 AT&T UNIX. This man page is derived from from The Mail Reference Manual originally written by Kurt Shoens. A revision for nail was done by Gunnar Ritter.