Changes From Version 8.12 of sendmail

This section contains information about the following topics.

• Support for TCP Wrappers From Version 8.12 of sendmail

• submit.cf Configuration File From Version 8.12 of sendmail

• Additional or Deprecated Command-Line Options From Version 8.12 of sendmail

• Additional Arguments for the PidFile and ProcessTitlePrefix Options From Version 8.12 of sendmail

• Additional Defined Macros From Version 8.12 of sendmail

• Additional Macros From Version 8.12 of sendmail

• Additional MAX Macros From Version 8.12 of sendmail

• Additional and Revised m4 Configuration Macros From Version 8.12 of sendmail

• Changes to the FEATURE() Declaration From Version 8.12 of sendmail

• Changes to the MAILER() Declaration From Version 8.12 of sendmail

• Additional Delivery Agent Flags From Version 8.12 of sendmail

• Additional Equates for Delivery Agents From Version 8.12 of sendmail

• Additional Queue Features From Version 8.12 of sendmail

• Changes for LDAP From Version 8.12 of sendmail

• Change to the Built-In Mailer From Version 8.12 of sendmail

• Additional Rule Sets From Version 8.12 of sendmail

• Changes to Files From Version 8.12 of sendmail

• sendmail Version 8.12 and IPv6 Addresses in Configuration

Support for TCP Wrappers From Version 8.12 of sendmail

TCP wrappers provide a way of implementing access controls by checking the address of a host requesting a particular network service against an access control list (ACL). Requests are granted or denied, accordingly. Besides providing this access control mechanism, TCP wrappers also log host requests for network services, which is a useful monitoring function. Examples of network services that might be placed under access control include rlogind, telnetd, and ftpd.

Starting with version 8.12, sendmail enables the use of TCP wrappers. This check does not bypass other security measures. By enabling TCP wrappers in sendmail, a check has been added to validate the source of a network request before the request is granted. See the hosts_access(4) man page.

---

Note - Support for TCP wrappers in inetd(1M) and sshd(1M) started with the Solaris 9 release.

---

For information about ACLs, see Using Access Control Lists to Protect Files in System Administration Guide: Security Services.

submit.cf Configuration File From Version 8.12 of sendmail

Starting with version 8.12, sendmail includes an additional configuration file, /etc/mail/submit.cf. This file, submit.cf, is used to run sendmail in mail-submission program mode instead of daemon mode. Mail-submission program mode, unlike daemon mode, does not require root privilege, so this new paradigm provides better security.

See the following list of functions for submit.cf:

• sendmail uses submit.cf to run in mail-submission program (MSP) mode, which submits email messages and can be started by programs (such as mailx), as well as by users. Refer to the descriptions of the -Ac option and the -Am option in the sendmail(1M) man page.

• submit.cf is used in the following operating modes:

  • -bm, which is the default operating mode

  • -bs, which uses standard input to run SMTP

  • -bt, which is the test mode that is used to resolve addresses

• sendmail, when using submit.cf, does not run as an SMTP daemon.

• sendmail, when using submit.cf, uses /var/spool/clientmqueue, the client-only mail queue, which holds messages that were not delivered to the sendmail daemon. Messages in the client-only queue are delivered by the client “daemon,” which is really acting as a client queue runner.

• By default, sendmail uses submit.cf periodically to run the MSP queue (otherwise known as the client-only queue), /var/spool/clientmqueue.

  /usr/lib/sendmail -Ac -q15m

Note the following:

• Starting with the Solaris 9 release, submit.cf is provided automatically.

• submit.cf does not require any planning or preliminary procedures prior to the installation of the Solaris 9 release or a more recent release.

• Unless you specify a configuration file, sendmail automatically uses submit.cf as required. Basically, sendmail knows which tasks are appropriate for submit.cf and which tasks are appropriate for sendmail.cf.

• submit.cf is not to be modified.

Functions That Distinguish sendmail.cf From submit.cf

The sendmail.cf configuration file is for the daemon mode. When using this file, sendmail is acting as a mail transfer agent (MTA), which is started by root.

/usr/lib/sendmail -L sm-mta -bd -q1h

See the following list of other distinguishing functions for sendmail.cf:

• By default, sendmail.cf accepts SMTP connections on ports 25 and 587.

• By default, sendmail.cf runs the main queue, /var/spool/mqueue.

Functional Changes From Version 8.12 of sendmail

With the addition of submit.cf, the following functional changes have occurred:

• Starting with version 8.12 of sendmail, only root can run the mail queue. For further details, refer to the changes that are described in the mailq(1) man page. For new task information, refer to Administering the Queue Directories (Task Map).

• The mail-submission program mode runs without root privilege, which might prevent sendmail from having access to certain files (such as the .forward files). Therefore, the -bv option for sendmail could give the user misleading output. No workaround is available.

• Prior to sendmail version 8.12, if you were not running sendmail in daemon mode, you would only prevent the delivery of inbound mail. Starting with sendmail version 8.12, if you are not running the sendmail daemon with the default configuration, you also prevent the delivery of outbound mail. The client queue runner (also known as the mail submission program) must be able to submit mail to the daemon on the local SMTP port. If the client queue runner tries to open an SMTP session with the local host and the daemon is not listening on the SMTP port, the mail remains in the queue. The default configuration does run a daemon, so this problem does not occur if you are using the default configuration. However, if you have disabled your daemon, refer to Managing Mail Delivery by Using an Alternate Configuration for a way to resolve this problem.

Additional or Deprecated Command-Line Options From Version 8.12 of sendmail

The following table describes additional or deprecated command-line options for sendmail. Other command-line options are described in the sendmail(1M) man page.

Table 14-19 Additional or Deprecated Command-Line Options From Version 8.12 of sendmail

Option	Description
-Ac	Indicates that you want to use the configuration file, submit.cf, even if the operation mode does not indicate an initial mail submission. For more information about submit.cf, refer to submit.cf Configuration File From Version 8.12 of sendmail.
-Am	Indicates that you want to use the configuration file, sendmail.cf, even if the operation mode indicates an initial mail submission. For more information, refer to submit.cf Configuration File From Version 8.12 of sendmail.
-bP	Indicates that you are printing the number of entries in each queue.
-G	Indicates that the message that is being submitted from the command line is for relaying, not for initial submission. The message is rejected if the addresses are not fully qualified. No canonicalization is done. As is noted in the Release Notes that are part of the sendmail distribution on ftp://ftp.sendmail.org, improperly formed messages might be rejected in future releases.
-L tag	Sets the identifier that is used for syslog messages to the supplied tag.
-q[!]I substring	Processes only jobs that contain this substring of one of the recipients. When ! is added, the option processes only jobs that do not have this substring of one of the recipients.
-q[!]R substring	Processes only jobs that contain this substring of the queue ID. When ! is added, the option processes only jobs that do not have this substring of the queue ID.
-q[!]S substring	Processes only jobs that contain this substring of the sender. When ! is added, the option processes only jobs that do not have this substring of the sender.
-qf	Processes saved messages in the queue once, without using the fork system call, and runs the process in the foreground. Refer to the fork(2) man page.
-qGname	Processes only the messages in the name queue group.
-qptime	Processes saved messages in the queue at a specific interval of time with a single child that is forked for each queue. The child sleeps between queue runs. This new option is similar to the -qtime, which periodically forks a child to process the queue.
-U	As is noted in the Release Notes that are part of the sendmail distribution on ftp://ftp.sendmail.org, this option is not available as of version 8.12. Mail user agents should use the -G argument.

Additional Arguments for the PidFile and ProcessTitlePrefix Options From Version 8.12 of sendmail

The following table describes additional macro-processed arguments for the PidFile and ProcessTitlePrefix options. For more information about these options, see the sendmail(1M) man page.

Table 14-20 Arguments for the PidFile and ProcessTitlePrefix Options

Macro	Description
${daemon_addr}	Provides daemon address (for example, 0.0.0.0)
${daemon_family}	Provides daemon family (for example, inet, and inet6)
${daemon_info}	Provides daemon information (for example, SMTP+queueing@00:30:00)
${daemon_name}	Provides daemon name (for example, MSA)
${daemon_port}	Provides daemon port (for example, 25)
${queue_interval}	Provides queue run interval (for example, 00:30:00)

Additional Defined Macros From Version 8.12 of sendmail

The following table describes additional macros that are reserved for use by the sendmail program. The macros' values are assigned internally. For more information, refer to the sendmail(1M) man page.

Table 14-21 Additional Defined Macros for sendmail

Macro	Description
${addr_type}	Identifies the current address as an envelope sender or a recipient address.
${client_resolve}	Holds the result of the resolve call for ${client_name}: OK, FAIL, FORGED, or TEMP.
${deliveryMode}	Specifies the current delivery mode sendmail is using instead of the value of the DeliveryMode option.
${dsn_notify}, ${dsn_envid}, ${dsn_ret}	Holds the corresponding DSN parameter values.
${if_addr}	Provides the interface's address for the incoming connection if the interface does not belong to the loopback net. This macro is especially useful for virtual hosting.
${if_addr_out}, ${if_name_out}, ${if_family_out}	Avoids the reuse of ${if_addr}. Holds the following values respectively. The address of the interface for the outgoing connection The host name of the interface for the outgoing connection The family of the interface for the outgoing connection
${if_name}	Provides the interface's host name for the incoming connection and is especially useful for virtual hosting.
${load_avg}	Checks and reports the current average number of jobs in the run queue.
${msg_size}	Holds the value of the message size (SIZE=parameter) in an ESMTP dialogue before the message has been collected. Thereafter, the macro holds the message size as computed by sendmail and is used in check_compat. For information about check_compat, refer to Table 14-25.
${nrcpts}	Holds the number of validated recipients.
${ntries}	Holds the number of delivery attempts.
${rcpt_mailer}, ${rcpt_host}, ${rcpt_addr}, ${mail_mailer}, ${mail_host}, ${mail_addr}	Holds the results of parsing the RCPT and MAIL arguments, which is the resolved right-hand side (RHS) triplet from the mail delivery agent ($#mailer), the host ($@host), and the user ($:addr).

Additional Macros From Version 8.12 of sendmail

In this section, you can find a table that describes the additional macros that are used to build the sendmail configuration file.

Table 14-22 Additional Macros Used to Build the sendmail Configuration File

Macro	Description
LOCAL_MAILER_EOL	Overrides the default end-of-line string for the local mailer.
LOCAL_MAILER_FLAGS	Adds Return-Path: header by default.
MAIL_SETTINGS_DIR	Contains the path (including the trailing slash) for the mail settings directory.
MODIFY_MAILER_FLAGS	Improves the *_MAILER_FLAGS. This macro sets, adds, or deletes flags.
RELAY_MAILER_FLAGS	Defines additional flags for the relay mailer.

Additional MAX Macros From Version 8.12 of sendmail

Use the following macros to configure the maximum number of commands that can be received before sendmail slows its delivery. You can set these MAX macros at compile time. The maximum values in the following table also represent the current default values.

Table 14-23 Additional MAX Macros

Macro	Maximum Value	Commands Checked by Each Macro
MAXBADCOMMANDS	25	Unknown commands
MAXNOOPCOMMANDS	20	NOOP, VERB, ONEX, XUSR
MAXHELOCOMMANDS	3	HELO, EHLO
MAXVRFYCOMMANDS	6	VRFY, EXPN
MAXETRNCOMMANDS	8	ETRN

---

Note - You can disable a macro's check by setting the macro's value to zero.

---

Additional and Revised m4 Configuration Macros From Version 8.12 of sendmail

This section contains a table of additional and revised m4 configuration macros for sendmail. Use the following syntax to declare these macros.

symbolic-name(`value')

If you need to build a new sendmail.cf file, refer to Building the sendmail.cf Configuration File in Chapter 13, Mail Services (Tasks).

Table 14-24 Additional and Revised m4 Configuration Macros for sendmail

m4 Macro	Description
FEATURE()	For details, refer to Changes to the FEATURE() Declaration From Version 8.12 of sendmail.
LOCAL_DOMAIN()	This macro adds entries to class w ($=w).
MASQUERADE_EXCEPTION()	A new macro that defines hosts or subdomains that cannot be masqueraded.
SMART_HOST()	This macro can now be used for bracketed addresses, such as user@[host].
VIRTUSER_DOMAIN() or VIRTUSER_DOMAIN_FILE()	When these macros are used, include $={VirtHost} in $=R. As a reminder, $=R is the set of host names that are allowed to relay.

Changes to the FEATURE() Declaration From Version 8.12 of sendmail

Refer to the following tables for information about the specific changes to the FEATURE() declarations.

To use the new and revised FEATURE names, use the following syntax.

FEATURE(`name', `argument')

If you need to build a new sendmail.cf file, refer to Building the sendmail.cf Configuration File in Chapter 13, Mail Services (Tasks).

Table 14-25 Additional and Revised FEATURE() Declarations

Name of FEATURE()	Description
compat_check	Argument: Refer to the example in the following paragraph. This new FEATURE() enables you to look for a key in the access map that consists of the sender address and the recipient address. This FEATURE() is delimited by the following string, <@>. sender@sdomain<@>recipient@rdomain is an example.
delay_checks	Argument: friend, which enables a spam-friend test, or hater, which enables a spam-hater test. A new FEATURE() that delays all checks. By using FEATURE(`delay_checks'), the rule sets check_mail and check_relay are not called when a client connects or issues a MAIL command respectively. Instead, these rule sets are called by the check_rcpt rule set. For details, refer to the /etc/mail/cf/README file.
dnsbl	Argument: This FEATURE()accepts a maximum of two arguments: DNS server name Rejection message A new FEATURE() that you can include multiple times to check the return values for DNS lookups. Note that this FEATURE() enables you to specify the behavior of temporary lookup failures.
enhdnsbl	Argument: domain name. A new FEATURE() that is an enhanced version of dnsbl, which enables you to check the return values for DNS lookups. For more information, refer to /etc/mail/cf/README.
generics_entire_domain	Argument: None. A new FEATURE() that you can also use to apply genericstable to subdomains of $=G.
ldap_routing	Argument: For details, refer to the “Release Notes” in http://www.sendmail.org. A new FEATURE() that implements LDAP address routing.
local_lmtp	Argument: Path name of an LMTP-capable mailer. The default is mail.local, which is LMTP capable in this Solaris release. A FEATURE() that now sets the delivery status notification (DSN) diagnostic-code type for the local mailer to the proper value of SMTP.
local_no_masquerade	Argument: None. A new FEATURE() that you can use to avoid masquerading for the local mailer.
lookupdotdomain	Argument: None. A new FEATURE() that you can also use to look up the .domain in the access map.
nocanonify	Argument: canonify_hosts or nothing. A FEATURE() that now includes the following features. Enables a list of domains, as specified by CANONIFY_DOMAIN or CANONIFY_DOMAIN_FILE, to be passed to the $[ and $] operators for canonification. Enables addresses that have only a host name, such as <user@host>, to be canonified, if canonify_hosts is specified as its parameter. Adds a trailing dot to addresses with more than one component.
no_default_msa	Argument: None. A new FEATURE() that turns off sendmail's default setting from m4–generated configuration files to “listen” on several different ports, an implementation of RFC 2476.
nouucp	Argument: reject, which does not allow the ! token, or nospecial, which does allow the ! token. A FEATURE() that determines whether to allow the ! token in the local part of an address.
nullclient	Argument: None. A FEATURE() that now provides the full rule sets of a normal configuration, allowing antispam checks to be performed.
preserve_local_plus_detail	Argument: None. A new FEATURE() that enables you to preserve the +detail portion of the address when sendmail passes the address to the local delivery agent.
preserve_luser_host	Argument: None. A new FEATURE() that enables you to preserve the name of the recipient host, if LUSER_RELAY is used.
queuegroup	Argument: None. A new FEATURE() that enables you to select a queue group that is based on the full email address or on the domain of the recipient.
relay_mail_from	Argument: The domain is an optional argument. A new FEATURE() that allows relaying if the mail sender is listed as a RELAY in the access map and is tagged with the From: header line. If the optional domain argument is given, the domain portion of the mail sender is also checked.
virtuser_entire_domain	Argument: None. A FEATURE() that you can now use to apply $={VirtHost}, a new class for matching virtusertable entries that can be populated by VIRTUSER_DOMAIN or VIRTUSER_DOMAIN_FILE. FEATURE(`virtuser_entire_domain') can also apply the class $={VirtHost} to entire subdomains.

The following FEATURE() declarations are no longer supported.

Table 14-26 Unsupported FEATURE() Declarations

Name of FEATURE()	Replacement
rbl	FEATURE(`dnsbl') and FEATURE(`enhdnsbl') replace this FEATURE(), which has been removed.
remote_mode	MASQUERADE_AS(`$S') replaces FEATURE(`remote_mode') in /etc/mail/cf/subsidiary.mc. $S is the SMART_HOST value in sendmail.cf.
sun_reverse_alias_files	FEATURE(`genericstable').
sun_reverse_alias_nis	FEATURE(`genericstable').
sun_reverse_alias_nisplus	FEATURE(`genericstable').

Changes to the MAILER() Declaration From Version 8.12 of sendmail

The MAILER() declaration specifies support for delivery agents. To declare a delivery agent, use the following syntax.

MAILER(`symbolic-name')

Note the following changes.

• In this new version of sendmail, the MAILER(`smtp') declaration now includes an additional mailer, dsmtp, which provides on-demand delivery by using the F=% mailer flag. The dsmtp mailer definition uses the new DSMTP_MAILER_ARGS, which defaults to IPC $h.

• Numbers for rule sets that are used by MAILERs have been removed. You now have no required order for listing your MAILERs except for MAILER(`uucp'), which must follow MAILER(`smtp') if uucp-dom and uucp-uudom are used.

For more information about mailers, refer to Mailers and sendmail. If you need to build a new sendmail.cf file, refer to Building the sendmail.cf Configuration File in Chapter 13, Mail Services (Tasks).

Additional Delivery Agent Flags From Version 8.12 of sendmail

The following table describes additional delivery agent flags, which by default are not set. These single-character flags are Boolean. You can set or unset a flag by including or excluding it in the F= statement of your configuration file, as shown in the following example.

Mlocal,    P=/usr/lib/mail.local, F=lsDFMAw5:/|@qSXfmnz9, S=10/30, R=20/40,
Mprog,     P=/bin/sh, F=lsDFMoqeu9, S=10/30, R=20/40, D=$z:/,
Msmtp,     P=[IPC], F=mDFMuX, S=11/31, R=21, E=\r\n, L=990,
Mesmtp,    P=[IPC], F=mDFMuXa, S=11/31, R=21, E=\r\n, L=990,
Msmtp8,    P=[IPC], F=mDFMuX8, S=11/31, R=21, E=\r\n, L=990,
Mrelay,    P=[IPC], F=mDFMuXa8, S=11/31, R=61, E=\r\n, L=2040,

Table 14-27 Additional Mailer Flags

Flag	Description
%	Mailers that use this flag do not attempt delivery to the initial recipient of a message or to queue runs unless the queued message is selected by using an ETRN request or one of the following queue options: -qI, -qR, or -qS.
1	This flag disables the ability of the mailer to send null characters (for example, \0).
2	This flag disables the use of ESMTP and requires that SMTP be used instead.
6	This flag enables mailers to strip headers to 7 bit.

Additional Equates for Delivery Agents From Version 8.12 of sendmail

The following table describes additional equates that you can use with the M delivery-agent definition command. The following syntax shows you how to append new equates or new arguments to the equates that already exist in the configuration file.

Magent-name, equate, equate, ...

The following example includes the new W= equate. This equate specifies the maximum time to wait for the mailer to return after all data has been sent.

Msmtp, P=[IPC], F=mDFMuX, S=11/31, R=21, E=\r\n, L=990, W=2m

When you modify the definition of a value for m4 configuration, use the syntax that is provided in the following example.

define(`SMTP_MAILER_MAXMSGS', `1000')

The preceding example places a limit of 1000 on the number of messages that are delivered per connection on an smtp mailer.

If you need to build a new sendmail.cf file, refer to Building the sendmail.cf Configuration File in Chapter 13, Mail Services (Tasks).

---

Note - Typically, you modify the equate definitions in the mailer directory only when you fine-tune.

---

Table 14-28 Additional Equates for Delivery Agents

Equate	Description
/=	Argument: Path to a directory Specifies a directory to apply chroot() to before the mailer program is executed
m=	Argument: Any of the following m4 values that have previously been defined with the define() routine SMTP_MAILER_MAXMSGS, for the smtp mailer LOCAL_MAILER_MAXMSGS, for the local mailer RELAY_MAILER_MAXMSGS, for the relay mailer Limits the number of messages that are delivered per connection on an smtp, local, or relay mailer
W=	Argument: An increment of time Specifies the maximum time to wait for the return of the mailer after all data has been sent

Additional Queue Features From Version 8.12 of sendmail

The following list provides details about additional queue features.

• This release supports multiple queue directories. To use multiple queues, supply a QueueDirectory option value in the configuration file that ends with an asterisk (*), as is shown in the following example.

  O QueueDirectory=/var/spool/mqueue/q*

  The option value, /var/spool/mqueue/q*, uses all of the directories (or symbolic links to directories) that begin with “q” as queue directories. Do not change the queue directory structure while sendmail is running. Queue runs create a separate process for running each queue unless the verbose flag (-v) is used on a nondaemon queue run. The new items are randomly assigned to a queue.

• The new queue file-naming system uses file names that are guaranteed to be unique for 60 years. This system allows queue IDs to be assigned without complex file-system locking and simplifies the movement of queued items between queues.

• Starting with version 8.12, only root can run the mail queue. For further details, refer to the changes that are described in the mailq(1) man page. For new task information, refer to Administering the Queue Directories (Task Map).

• To accommodate envelope splitting, queue file names are now 15–characters long, rather than 14–characters long. File systems with a 14–character name limit are no longer supported.

For task information, refer to Administering the Queue Directories (Task Map).

Changes for LDAP From Version 8.12 of sendmail

The following list describes changes in the use of the Lightweight Directory Access Protocol (LDAP) with sendmail.

• LDAPROUTE_EQUIVALENT() and LDAPROUTE_EQUIVALENT_FILE() permit you to specify equivalent host names, which are replaced by the masquerade domain name for LDAP routing lookups. For more information, refer to /etc/mail/cf/README.

• As noted in the Release Notes that are part of the sendmail distribution at ftp://ftp.sendmail.org, the LDAPX map has been renamed to LDAP. Use the following syntax for LDAP.

  Kldap ldap options

• This release supports the return of multiple values for a single LDAP lookup. Place the values to be returned in a comma-separated string with the -v option, as is shown.

  Kldap ldap -v"mail,more-mail"

• If no LDAP attributes are specified in an LDAP map declaration, all attributes that are found in the match are returned.

• This version of sendmail prevents commas in quoted key and value strings in the specifications of the LDAP alias file from dividing a single entry into multiple entries.

• This version of sendmail has a new option for LDAP maps. The option -Vseparator enables you to specify a separator so that a lookup can return both an attribute and a value that are separated by the relevant separator.

• In addition to using the %s token to parse an LDAP filter specification, you can use the new token, %0, to encode the key buffer. The %0 token applies a literal meaning to LDAP special characters.

The following example shows how these tokens differ for a “*” lookup.

Table 14-29 Comparison of Tokens

LDAP Map Specification	Specification Equivalent	Result
-k"uid=%s"	-k"uid=*"	Matches any record with a user attribute
-k"uid=%0"	-k"uid=\2A"	Matches a user with the name “*”

The following table describes additional LDAP map flags.

Table 14-30 Additional LDAP Map Flags

Flag	Description
-1	Requires a single match to be returned. If more than one match is returned, the results are the equivalent of no records being found.
-r never|always|search|find	Sets the LDAP alias dereference option.
-Z size	Limits the number of matches to return.

Change to the Built-In Mailer From Version 8.12 of sendmail

The old [TCP] built-in mailer is not available. Use the P=[IPC] built-in mailer instead. The interprocess communications ([IPC]) built-in mailer now enables delivery to a UNIX domain socket on systems that support it. You can use this mailer with LMTP delivery agents that listen on a named socket. An example mailer might resemble the following.

Mexecmail, P=[IPC], F=lsDFMmnqSXzA5@/:|, E=\r\n, 
S=10, R=20/40, T=DNS/RFC822/X-Unix, A=FILE /var/run/lmtpd

The first mailer argument in the [IPC] mailer is now checked for a legitimate value. The following table provides possible values for the first mailer argument.

Table 14-31 Possible Values for the First Mailer Argument

Value	Description
A=FILE	Use for UNIX domain socket delivery
A=TCP	Use for TCP/IP connections
A=IPC	Is no longer available as a first mailer argument

Additional Rule Sets From Version 8.12 of sendmail

The following table lists the additional rule sets and describes what the rule sets do.

Table 14-32 New Rule Sets

Set	Description
check_eoh	Correlates information that is gathered between headers and checks for missing headers. This rule set is used with the macro storage map and is called after all of the headers have been collected.
check_etrn	Uses the ETRN command (as check_rcpt uses RCPT).
check_expn	Uses the EXPN command (as check_rcpt uses RCPT).
check_vrfy	Uses the VRFY command (as check_rcpt uses RCPT).

The following list describes additional rule set features.

• Numbered rule sets are also named, but the rule sets can still be accessed by their numbers.

• The H header configuration file command allows for a default rule set to be specified for header checks. This rule set is called only if the individual header has not been assigned its own rule set.

• Comments in rule sets (that is, text within parentheses) are not removed if the configuration file version is nine or greater. For example, the following rule matches the input token (1), but does not match the input token.

  R$+ (1)        $@ 1

• sendmail accepts the SMTP RSET command even when it rejects commands because of TCP wrappers or the check_relay rule set.

• You receive a warning if you set the OperatorChars option multiple times. Also, do not set OperatorChars after the rule sets are defined.

• The name of the rule set, as well as its lines, are ignored if an invalid rule set is declared. The rule set lines are not added to S0.

Changes to Files From Version 8.12 of sendmail

Note the following changes.

• Starting in the Solaris 10 release, to support a read-only /usr file system, the contents of the /usr/lib/mail directory has been moved to the /etc/mail/cf directory. For details, refer to Contents of the /etc/mail/cf Directory. Note, however, that the shell scripts /usr/lib/mail/sh/check-hostname and /usr/lib/mail/sh/check-permissions are now in the /usr/sbin directory. See Other Files Used for Mail Services. For backward compatibility, symbolic links point to each file's new location.

• The new name for /usr/lib/mail/cf/main-v7sun.mc is /etc/mail/cf/cf/main.mc.

• The new name for /usr/lib/mail/cf/subsidiary-v7sun.mc is /etc/mail/cf/cf/subsidiary.mc.

• The helpfile is now located in /etc/mail/helpfile. The old name (/etc/mail/sendmail.hf) has a symbolic link that points to the new name.

• The trusted-users file is now located in /etc/mail/trusted-users. During an upgrade, if the old name (/etc/mail/sendmail.ct) is detected, but not the new name, a hard link from the old name to the new name is created. Otherwise, no change is made. The default content is root.

• The local-host-names file is now located in /etc/mail/local-host-names. During an upgrade, if the old name (/etc/mail/sendmail.cw) is detected, but not the new name, a hard link from the old name to the new name is created. Otherwise, no change is made. The default content is zero length.

sendmail Version 8.12 and IPv6 Addresses in Configuration

Starting with version 8.12 of sendmail, IPv6 addresses that are used in configuration should be prefixed with the IPv6: tag to identify the address properly. If you are not identifying an IPv6 address, a prefix tag is not used.