TMAIL(LOCAL)TMAIL(LOCAL)NAMEtmail - Mail Delivery Module
SYNOPSIStmail [-D] [-f from_name] [-I inbox_specifier]
user[+folder] ...
DESCRIPTIONtmail delivers mail to a user's INBOX or a designated
folder. tmail may be configured as a drop-in replacement
for binmail(1), mail.local(1) or any program intended for
use for mail delivery by sendmail(8).
tmail is intended to be used for direct delivery by the
mailer daemon; dmail(1) is the preferred tool for user
applications, e.g. a mail delivery filter such as
filter(1L) or procmail(1). If tmail is used for a user
application, then the calling program must be aware of the
restrictions noted below.
When tmail exits, it returns exit status values to enable
sendmail(8) to determine whether a message was delivered
successfully or had a temporary (requeue for later
delivery) or permanent (return to sender) failure.
If the +folder extension is included in the user argument,
tmail will attempt to deliver to the designated folder.
If the folder does not exist or the extension is not
included, the message is delivered to the user's INBOX.
If delivery is to INBOX and no INBOX currently exists,
tmail will create a new INBOX, using the -I flag if
specified. tmail recognizes the format of an existing
INBOX or folder, and appends the new message in that
format.
The -D flag specifies debugging; this enables additional
message telemetry.
The -f or -r flag is used by sendmail(8) to specify a
Return-Path. The header
Return-Path: <from_name>
is prepended to the message before delivery.
The -I flag is used by sendmail(8) to specify an
alternative INBOX name. This affects the location and
format of INBOX, and requires privileges. If specified,
it should be in one of three forms:
The first form of argument to -I is the string "INBOX",
which means to write to the system default inbox using the
system default mailbox format. These system defaults are
defined when the c-client library is built.
The second form of argument to -I is a delivery
specification, consisting of "#driver.", a c-client
mailbox format driver name, "/", and a file name. This
will write to the specified file in the specified format.
For example, #driver.mbx/INBOX will write to file "INBOX"
in the home directory in mbx format; and
#driver.unix/mail/incoming will write to file "incoming"
in the user's "mail" subdirectory in unix (default UNIX)
format.
The third form of argument to -I is any other name.
Normally, this will write to the specified file on the
user's home directory in the specified format. However,
certain names are special. These are:
value equivalant to
------------------
INBOX.MTX #driver.mtx/INBOX.MTX
mbox #driver.unix/mbox
mail.txt #driver.tenex/mail.txt
If -I is not specified, the default action is -I INBOX.
If multiple recipients are specified on the command line,
tmail spawns one child process per recipient to perform
actual delivery. This way of calling tmail is not
recommended; see below under RESTRICTIONS.
INSTALLATION
If tmail is to be used for mail delivery from sendmail(8),
it must be installed setuid root.
tmail is invoked from sendmail.cf. Look for the "Mlocal"
line, and substitute the path name for the tmail binary in
place of /bin/mail, /usr/lib/mail.local, etc. You should
also add the flag to invoke tmail with CRLF style
newlines; this is usually done with E=\r\n in the Mlocal
line.
For example, this is what is used on the author's system
with sendmail version 8:
Mlocal, P=/usr/local/etc/tmail, F=lsDFMAw5:/|@qPrn+,
S=10/30, R=20/40, E=\r\n, T=DNS/RFC822/X-Unix,
A=tmail $u
If tmail is to be called with the -I flag, it must be
invoked with both real and effective UID root. Many
sendmail configurations invoke the local mailer as the
sending user when that user is local, which will prevent
-I from working.
SECURITY CONSIDERATIONS
If tmail is invoked by an ordinary user, the Received:
header line will indicate the name or UID of the user that
invoked it.
Ordinary users are not permitted to use the -I flag since
otherwise a user could create any file on another user's
directory.
tmail can deliver mail to home directories. In addition,
tmail can be used to deliver mail to other mail folders in
a home directory or an inferior directory of a home
directory.
RESTRICTIONS
The calling program should invoke tmail with CRLF
newlines, otherwise tmail will complain in syslog.
Absolute pathnames and ~user specifications are not
permitted in +folder extensions.
Ordinary users are not permitted to use the -I flag.
IMAP4 namespace names are not yet supported in +folder
extensions.
It is not possible to use tmail to deliver to mh(1) format
mailboxes.
If delivery to multiple users is specified and delivery to
any single user fails, the entire delivery will be
reported as having failed, even though delivery to other
users may have succeeded. If tmail is used for mail
delivery from sendmail(8), a separate tmail invocation
should be done for each user. Otherwise a delivery
failure for a single user in a message going to multiple
users will cause multiple deliveries to all the other
users every time sendmail(8), retries.
AUTHOR
Mark Crispin, MRC@CAC.Washington.EDU
SEE ALSObinmail(1)sendmail(8)
Version 4.1 TMAIL(LOCAL)
