changes.me

早期freebsd实现

as required by RFC 821.
.sh 2 "Eight-Bit Clean
.pp
Previous versions of sendmail used the 0200 bit for quoting.  This
version avoids that use.
However, you can set option `7' to get seven bit stripping
for compatibility with RFC 821,
which is a 7-bit protocol.
This option says ``strip to 7 bits on input''.
.pp
Individual mailers can still produce seven bit out put using the
`7' mailer flag.
This flag says ``strip to 7 bits on output''.
.sh 2 "User Database"
.pp
The User Database (UDB) is an as-yet experimental attempt to provide
unified large-site name support.
We are installing it at Berkeley;
future versions may show significant modifications.
Briefly, UDB contains a database that is intended to contain
all the per-user information for your workgroup,
such as people's full names, their .plan information,
their outgoing mail name, and their mail drop.
.pp
The user database allows you to map both incoming and outgoing
addresses, much like IDA.  However, the interface is still
better with IDA;
in particular, the alias file with incoming/outgoing marks
provides better locality of information.
.sh 2 "Improved BIND Support"
.pp
The BIND support, particularly for MX records, had a number of
annoying ``features'' which have been removed in this release.  In
particular, these more tightly bind (pun intended) the name server
to sendmail, so that the name server resolution rules are incorporated
directly into sendmail.
.pp
The major change has been that the $[ ... $] operator didn't fully
qualify names that were in DNS as A or MX records.  Version 8 does
this qualification.
.pp
This has proven to be an annoyance in Sun shops,
who often still run without BIND support.
However, it is really critical that this be supported,
since MX records are mandatory.
In SunOS you can choose either MX support or NIS support,
but not both.
This is fixed in Solaris,
and some
.i sendmail
support to allow this in SunOS should be forthcoming in a future release.
.sh 2 "Keyed Files"
.pp
Generalized keyed files is an idea taken directly from IDA sendmail
(albeit with a completely different implementation).
They can be useful on large sites.
.pp
Version 8 includes the following built-in map classes:
.ip dbm
Support for the ndbm(3) library.
.ip hash
Support for the ``Hash'' type from the new Berkeley db(3) library.
this library provides substantially better database support
than ndbm(3),
including in-memory caching,
arbitrarily long keys and values,
and better disk utilization.
.ip btree
Support for the ``B-Tree'' type from the new Berkeley db(3) library.
B-Trees provide better clustering than Hashed files
if you are fetching lots of records that have similar keys,
such as searching a dictionary for words beginning with ``detr''.
.ip nis
Support for NIS (a.k.a. YP) maps.
NIS+ is not supported in this version.
.ip host
Support for DNS lookups.
.ip dequote
A ``pseudo-map'' (that is, once that does not have any external data)
that allows a configuration file to break apart a quoted string
in the address.
This is necessary primarily for DECnet addresses,
which often have quoted addresses that need to be unwrapped on gateways.
.sh 2 "Multi-Word Classes & Macros in Classes"
.pp
Classes can now be multiple words.  For example,
.(b
CShofmann.CS.Berkeley.EDU
.)b
allows you to match the entire string ``hofmann.CS.Berkeley.EDU''
using the single construct ``$=S''.
.pp
Class definitions are now allowed to include macros \*- for example:
.(b
Cw$k
.)b
is legal.
.sh 2 "IDENT Protocol Support"
.pp
The IDENT protocol as defined in RFC 1413 [RFC1413] is supported.
However, many systems have a TCP/IP bug that renders this useless,
and the feature must be turned off.
Roughly, if one of these system receives a
.q "No route to host"
message (ICMP message ICMP_UNREACH_HOST) on
.i any
connection, all connections to that host are closed.
Some firewalls return this error if you try to connect
to the IDENT port,
so you can't receive email from these hosts on these systems.
It's possible that if the firewall used a more specific message
(such as ICMP_UNREACH_PROTOCOL, ICMP_UNREACH_PORT or ICMP_UNREACH_NET_PROHIB)
it would work, but this hasn't been verified.
.pp
IDENT protocol support cannot be used on
4.3BSD,
Apollo DomainOS,
Apple A/UX,
ConvexOS,
Data General DG/UX,
HP-UX,
Sequent Dynix,
or
Ultrix.
It seems to work on
4.4BSD,
IBM AIX 3.x,
OSF/1,
SGI IRIX,
Solaris,
and
SunOS.
.sh 2 "Separate Envelope/Header Processing
.pp
Since the From: line is passed in separately from the envelope
sender, these have both been made visible; the $g macro is set to
the envelope sender during processing of mailer argument vectors
and the header sender during processing of headers.
.pp
It is also possible to specify separate per-mailer envelope and
header processing.  The SenderRWSet and RecipientRWset arguments
for mailers can be specified as ``envelope/header'' to give different
rewritings for envelope versus header addresses.
.sh 2 "Owner-List Propagates to Envelope
.pp
When an alias has an associated owner-list name, that alias is used
to change the envelope sender address.  This will cause downstream
errors to be returned to that owner.
.pp
Some people find this confusing
because the envelope sender is what appears in the first
``From_'' line in UNIX messages
(that is, the line beginning ``From<space>''
instead of ``From:'';
the latter is the header from, which
.i does
indicate the sender of the message).
In previous versions,
.i sendmail
has tried to avoid changing the envelope sender
for back compatibility with UNIX convention;
at this point that back compatibility is creating too many problems,
and it is necessary to move forward into the 1980s.
.sh 2 "Command Line Flags"
.pp
The
.b \-B
flag has been added to pass in body type information.
.pp
The
.b \-p
flag has been added to pass in protocol information
that was previously passed in by defining the
.b $r
and
.b $s
macros.
.pp
The
.b \-X
flag has been added to allow logging of all protocol in and
out of sendmail for debugging.
You can set
.q "\-X filename"
and a complete transcript will be logged in that file.
This gets big fast: the option is only for debugging.
.pp
The
.b \-q
flag can limit limit a queue run to specific recipients,
senders, or queue ids using \-qRsubstring, \-qSsubstring, or
\-qIsubstring respectively.
.sh 2 "New Configuration Line Types
.pp
The `T' (Trusted users) configuration line has been deleted.  It
will still be accepted but will be ignored.
.pp
The `K' line has been added to declare database maps.
.pp
The `V' line has been added to declare the configuration version
level.
.pp
The `M' (mailer) line takes a D= field to specify execution
directory.
.sh 2 "New and Extended Options"
.pp
Several new options have been added, many to support new features,
others to allow tuning that was previously available only by
recompiling.  Briefly:
.nr ii 0.5i
.ip A
The alias file specification can now be a list of alias files.
Also, the configuration can specify a class of file.
For example, to search the NIS aliases, use
.q OAnis:mail.aliases .
.ip b
Insist on a minimum number of disk blocks.
.ip C
Delivery checkpoint interval.  Checkpoint the queue (to avoid
duplicate deliveries) every C addresses.
.ip E
Default error message.  This message (or the contents of the
indicated file) are prepended to error messages.
.ip G
Enable GECOS matching.  If you can't find a local user name
and this option is enabled, do a sequential scan of the passwd
file to match against full names.  Previously a compile option.
.ip h
Maximum hop count.  Previously this was compiled in.
.ip I
This option has been extended to allow setting of resolver parameters.
.ip j
Send errors in MIME-encapsulated format.
.ip J
Forward file path.  Where to search for .forward files \*- defaults
to $HOME/.forward.
.ip k
Connection cache size.  The total number of connections that will
be kept open at any time.
.ip K
Connection cache lifetime.  The amount of time any connection
will be permitted to sit idle.
.ip l
Enable Errors-To: header.  These headers violate RFC 1123;
this option is included to provide back compatibility with
old versions of sendmail.
.ip O
Incoming daemon options (e.g., use alternate SMTP port).
.ip p
Privacy options.  These can be used to make your SMTP server
less friendly.
.ip r
This option has been extended to allow finer grained control
over timeouts.
For example, you can set the timeout for SMTP commands individually.
.ip R
Don't prune route-addrs.  Normally, if version 8 sees an address
like "<@hostA,@hostB:user@hostC>, sendmail will try to strip off
as much as it can (up to user@hostC) as suggested by RFC 1123.
This option disables that behaviour.
.ip T
The
.q "Return To Sender"
timeout has been extended
to allow specification of a warning message interval,
typically something on the order of four hours.
If a message cannot be delivered in that interval,
a warning message is sent back to the sender
but the message continues to be tried.
.ip U
User database spec.  This is still experimental.
.ip V
Fallback ``MX'' host.  This can be thought of as an MX host
that applies to all addresses that has a very high preference
value (that is, use it only if everything else fails).
.ip w
If set, assume that if you are the best MX host for a host,
you should send directly to that host.  This is intended
for compatibility with UIUC sendmail, and may have some
use on firewalls.
.ip 7
Do not run eight bit clean.  Technically, you have to assert
this option to be RFC 821 compatible.
.sh 2 "New Mailer Definitions"
.ip L=
Set the allowable line length.  In V5, the L mailer flag implied
a line length limit of 990 characters; this is now settable to
an arbitrary value.
.ip F=a
Try to use ESMTP.  It will fall back to SMTP if the initial
EHLO packet is rejected.
.ip F=b
Ensure a blank line at the end of messages.  Useful on the
*file* mailer.
.ip F=c
Strip all comments from addresses; this should only be used as
a last resort when dealing with cranky mailers.
.ip F=g
Never use the null sender as the envelope sender, even when
running SMTP.  This violates RFC 1123.
.ip F=7
Strip all output to this mailer to 7 bits.
.ip F=L
Used to set the line limit to 990 bytes for SMTP compatibility.
It now does that only if the L= keyletter is not specified.
This flag is obsolete and should not be used.
.sh 2 "New or Changed Pre-Defined Macros"
.ip $k
UUCP node name from uname(2).
.ip $m
Domain part of our full hostname.
.ip $_
RFC 1413-provided sender address.
.ip $w
Previously was sometimes the full domain name, sometimes
just the first word.  Now guaranteed to be the first word
of the domain name (i.e., the host name).
.ip $j
Previously had to be defined \*- it is now predefined to be
the full domain name, if that can be determined.  That is,
it is equivalent to $w.$m.
.sh 2 "New and Changed Classes"
.ip $=k
Initialized to contain $k.
.ip $=w
Now includes
.q [1.2.3.4]
(where 1.2.3.4 is your IP address)
to allow the configuration file to recognize your own IP address.
.sh 2 "New Rewriting Tokens"
.pp
The
.b $&