- AliasFile=file
Use alternate alias file.
- AlertTmpFailure
If set,
sendmail
logs transient error messages as
LOG_ALERT
messages at
Loglevel>=2,
else it logs as
LOG_INFO
messages at
Loglevel>8.
- HoldExpensive
On mailers that are considered ``expensive'' to connect to,
do not initiate immediate connection.
This requires queuing.
- CheckpointInterval=N
Checkpoint the queue file after every
N
successful deliveries (default 10).
This avoids excessive duplicate deliveries
when sending to long mailing lists
interrupted by system crashes.
- DeliveryMode=x
Set the delivery mode to
x.
The delivery modes are:
- b
background (asynchronous) delivery.
- d
deferred; the same as
q
except that database lookups
(DNS and NIS lookups) are avoided.
- i
interactive (synchronous) delivery.
- q
queue only; expect the messages to be delivered
the next time when the queue is run.
- ErrorMode=x
Set error processing to mode
x.
The valid modes are:
- e
do special processing for the BerkNet.
- m
mail back the error message.
- p
print the errors on the terminal
(default).
- q
throw away error messages
(only exit status is returned).
- w
``write'' back the error message
(or mail it back if the sender is not logged in).
If the text of the message is not mailed back by modes
m
or
w,
and if the sender is local to this machine, then
a copy of the message is appended to the file
dead.letter
in the sender's home directory.
- SaveFromLine
Save UNIX -style
``From'' lines at the front of messages.
- MaxHopCount=N
Use this option to set the maximum number of times a message is allowed to
``hop'' before it is considered in a loop.
- IgnoreDots
Use this option to instruct
sendmail
to ignore dots in a line by themselves
as a message terminator.
- SendMimeErrors
Send error messages in MIME format.
- ConnectionCacheTimeOut=timeout
Set connection cache timeout.
- ConnectionCacheSize=N
Set connection cache size.
- Loglevel=n
Set the log level.
- MeToo
Send to ``me'' (the sender) also if the sender is in an alias expansion.
- CheckAliases
Validate the right hand side of aliases during a
newaliases
command. See
newaliases(1M).
- OldStyleheaders
Set this option to have
old style headers in the message. If
not set,
this message is guaranteed to have new style headers
(i.e., commas instead of spaces between addresses). If
set, an adaptive algorithm is used that will correctly
determine the header format in most cases.
- QueueDirectory=queuedir
Select the directory in which the messages are to be queued.
- StatusFile=file
Use this option to save mail traffic statistics into the specified
file.
- DeadLetterDrop
Define the location of the system-wide
dead.letter
file.
- ConnectOnlyTo
Override the connection address (for testing).
- TrustedUser
Define trusted user for changing the file ownership and also for
starting the daemon.
- ControlSocketName
Set this option to create a daemon control socket. This socket
allows an external program to control and query status from the running
sendmail
daemon
via a named socket.
- MaxMimeHeaderLength
Limit the size of MIME
headers and parameters within those headers. This option
is intended to protect mail user agents (MUAs) from buffer
overflow attacks.
- MaxAliasRecursion
Specify the maximum depth of alias recursion.
- PidFile
Define the location of the pid file. The
/etc/mail/sendmail.pid
file will be the default even if this option is not set.
- ProcessTitlePrefix
Specify a prefix string for the process title shown in
ps
listings.
- DataFileBufferSize
Control the maximum size of a memory-buffered data (df) file before a
disk-based file is used.
- XscriptFileBufferSize
Control the maximum size of a memory-buffered transcript (xf) file before a
disk-based file is used.
- AuthMechanisms
Use this option to list all the authentication mechanisms used.
- DefaultAuthInfo
Set filename that contains authentication information for
outgoing connections. This file must contain the user id, the
authorization id, the password (plain text), and the realm to use,
each on a separate line and must be readable by root (or the trusted
user) only. If no realm is specified,
$j
will be used.
- AuthOptions
If this option is set to 'A' then the
AUTH=
parameter for the
MAIL FROM command is issued only when the authentication succeeds.
- LDAPDefaultSpec
Default map specification for LDAP maps. The
value should contain only LDAP specific settings like
``-h host -p port -d bindDN'',
etc. The settings will be used for all LDAP
maps unless they are specified in the individual map specification
(K
command).
- CACERTPath
Path to directory with certs of CAs.
- CACERTFile
File containing one CA cert.
- ServerCertFile
File containing the cert of the server; i.e., this cert
is used when
sendmail
acts as a server.
- ServerKeyFile
File containing the private key belonging to the server cert.
- ClientCertFile
File containing the cert of the client; i.e., this cert is used when
sendmail
acts as a client.
- ClientKeyFile
File containing the private key belonging to the client cert.
- DHParameters
File containing the DH parameters.
- RandFile
File containing random data (use prefix
file:)
or the
name of the UNIX socket if EGD is used (use prefix
egd:).
- Timeout.control
Set this option to limit the total time spent in satisfying a control
socket request.
- Timeout.resolver.retrans
Use this option to set the resolver's retransmission time interval in seconds.
This also sets
Timeout.resolver.retrans.first
and
Timeout.resolver.retrans.normal
options.
- Timeout.resolver.retrans.first
Use this option to set the resolver's retransmission time interval in seconds
for the first attempt to deliver a message.
- Timeout.resolver.retrans.normal
Use this option to set the resolver's retransmission time interval in seconds
for all resolver lookups except the first delivery attempt.
- Timeout.resolver.retry
Use this option to set the number of times to retransmit a resolver query.
This also sets
Timeout.resolver.retry.first
and
Timeout.resolver.retry.normal
options.
- Timeout.resolver.retry.first
Use this option to set the number of times to retransmit a resolver query for
the first attempt to deliver a message.
- Timeout.resolver.retry.normal
Use this option to set the number of times to retransmit a resolver query for
all resolver lookups except the first delivery attempt.
- Timeout.queuereturn=time
Use this option to set the timeout on undelivered messages in the queue to the
specified time. The
failed messages will be returned to the sender after the delivery fails for
this amount of time (e.g., because of a host being down). The
default is three days.
- UserDatabaseSpec=userdatabase
Set this option to get forwarding information from the user database. You
can consider this as an adjunct to the aliasing mechanism,
except that the database is intended to be distributed;
aliases are local to a particular host.
- ForkEachJob
Use this option to fork each job during queue runs.
This may be convenient on memory-poor machines.
- SevenBitInput
Use this option to strip incoming messages to seven bits.
- EightBitMode=mode
Set the handling of 8-bit input to 7-bit destinations. Mode can be
set to the following values:
- m
Convert to 7-bit MIME format.
- p
Pass it as eight bits.
- s
Bounce the mail.
- MInQueueAge=timeout
Use this option to set the time interval between attempts to send a message from the queue.
- DefaultCharSet=charset
Use this option to set the default character-set used to label 8-bit data
that is not otherwise labeled.
- DialDelay=sleeptime
If opening a connection fails, sleep for
sleeptime
seconds and try again. This is useful on dial-on-demand sites.
- NoRecipientAction=action
Use this option to set the behaviour when there are no recipient headers
(To:, Cc: or Bcc:) in a message to
action.
The
action
can be set to the following values:
- none
Leaves the message unchanged.
- add-to
Adds a
To:
header with the envelope recipients.
- add-apparently-to
Adds an
Apparently-To:
header with the envelope recipients.
- add-bcc
Adds an empty
Bcc:
- add-to-undisclosed
Adds a header reading
To:undisclosed-recipients:
- MaxDaemonChildren=N
Use this option to set the maximum number of children that an incoming
SMTP daemon will allow to spawn at any time to
N.
- ConnectionRateThrottle=N
Use this option to set the maximum number of connections per second to
the SMTP port to
N.
- AutoRebuildAliases
Use this option to rebuild the alias database
when needed. Setting this option may cause excessive
overhead and is not recommended.
- DontProbeInterfaces
Use this option to turn off the inclusion of all
the interface names in
$=w
on startup. In particular,
if you have many virtual interfaces, this option
speeds up the startup. However, unless you make other
arrangements, mails sent to those addresses will
bounce. This is useful for sending mail to hosts
which have dynamically assigned names.
- DontBlameSendmail=options
This
options
allows you to bypass some of
sendmail
file security checks at the expense of system security. This
should be used only if you are aware of
the consequences. The options available for
DontBlameSendmail
are:
- Safe
- AssumeSafeChown
- ClassFileInUnsafeDirPath
- ErrorHeaderInUnsafeDirPath
- GroupWritableDirPathSafe
- GroupWritableForwardFileSafe
- GroupWritableIncludeFileSafe
- GroupWritableAliasFile
- HelpFileinUnsafeDirPath
- WorldWritableAliasFile
- ForwardFileInGroupWritableDirPath
- IncludeFileInGroupWritableDirPath
- ForwardFileInUnsafeDirPath
- IncludeFileInUnsafeDirPath
- ForwardFileInUnsafeDirPathSafe
- IncludeFileInUnsafeDirPathSafe
- MapInUnsafeDirPath
- LinkedAliasFileInWritableDir
- LinkedClassFileInWritableDir
- LinkedForwardFileInWritableDir
- LinkedIncludeFileInWritableDir
- LinkedMapInWritableDir
- LinkedServiceSwitchFileInWritableDir
- FileDeliveryToHardLink
- FileDeliveryToSymLink
- WriteMapToHardLink
- WriteMapToSymLink
- WriteStatsToHardLink
- WriteStatsToSymLink
- RunProgramInUnsafeDirPath
- RunWritableProgram
- DontInitGroups=True|False
Set this option to true, to prevent program deliveries from picking up extra
group privileges.
- MaxRecipientsPerMessage=no_of_recipients
Use this option to limit the number of recipients,
no_of_recipients
that will be accepted in a single SMTP transaction. After this number is
reached,
sendmail
starts returning "452 Too many recipients" to all
RCPT
commands. This can be used to limit the number of recipients per envelope
(in particular, to discourage use of the server for spamming).
Note:
A better approach is to restrict relaying entirely.
- MaxHeadersLength=max_header_length
Use this option to specify the maximum length of the sum of all headers,
max_header_length.
This can be used to prevent a Denial-of-Service(DoS) attack.
- RunAsUser=user
Use this option to enable
sendmail
do a
setuid
to that
user
early in processing to avoid potential security problems.
However, this means that
/var/spool/mqueue
directory owned by the
user
and all
.forward
and
:include:
files must be readable by that
user,
and all files to be written must be writable by that
user,
and all programs will be executed by that
user.
It is also incompatible with the
SafeFileEnvironment
option. In other words, it may not actually add much to security.
However, it should be useful on firewalls and other places where
users do not have accounts and the
aliases
file is well constrained.
- SafeFileEnvironment=option
Files named as delivery targets must be regular files in addition
to the regular checks in order to use this option. Also, if the
option
is non-null, then it is used as the name of a directory that is used as a
chroot()
environment for the delivery; the file names listed in an alias or forward
should include the name of this root.
- QueueSortOrder=option
Use this option to sort the queue based on the following values:
- host
This makes better use of the connection cache, but may delay more
``interactive'' messages behind large backlogs under some circumstances.
It is recommended to use this option if you have high speed links or do not
process too many
``batch'' messages; it might not perform better, if you are using something
like PPP on a 14.4 modem.
- time
This option causes the queue to be sorted strictly on the time of submission.
This might adversely affect the performance over slow lines and on nodes with
heavy traffic.
Also, this does not guarantee that jobs will be delivered in submission
order unless you set
DeliveryMode=queue
option.
In general, it should be used only on the command line, and
in conjunction with
-qRhost.domain.
- Filename
This option sorts the queue by filename. This avoids opening
and reading each queue file while preparing to run the queue. This will speed
up the queue processing.
- PrivacyOptions=flag
The
flag
can be set to the following values:
- public
Allow open access.
- needmailhelo
Insist on HELO (or EHLO) before the MAIL command.
- needexpnhelo
Insist on HELO (or EHLO) before the EXPN command.
- noexpn
Disallow EXPN command totally.
- needvrfyhelo
Insist on HELO (or EHLO) before the VRFY command.
- novrfy
Disallow VRFY command totally.
- restrictmailq
Restrict mailq command.
- restrictqrun
Restrict -q command-line flag.
- noreceipts
Do not return success DSN's.
- goaway
Disallow essentially all SMTP status queries.
- authwarnings
Put
X-Authentication-Warning
headers in messages if HELO was not used inside SMTP transaction.
- noverb
Flag to disable the SMTP VERB command.
- noetrn
Flag to disable the SMTP ETRN command.
By default,
authwarnings
and
restrictqrun
are enabled.
- DaemonPortOptions=field1=value,field2=value,...
The fields currently supported by
sendmail
are:
- Family
The values can be either
inet
or
inet6.
The default value is
inet.
- Address
IP address or hostname
- Name
Name of the agent
(MTA
or
MSA)
- Port
Port number (for
Name=MSA,
the port number should be 587)
- Send
Send buffer size
- Receive
Receive buffer size
- Listen
Listen queue size
- M
Modifier flags.
Following are the values to which the modifier flag
can be set:
- a
Require authentication.
- b
Bind to interface through which mail has been received.
- c
Pass the address for canonification.
- f
Enable fully qualified address for From address.
- h
Use name of interface for outgoing HELO command.
- u
Disable fully qualified address for From address.
- C
Do not pass the address for canonification.
- E
Turn off ETRN connections.
Note:
In order to use the IPv6 feature, you need to set the
DaemonPortOptions
with
Family=inet6.
If this option is set with
Name=MSA,
a separate daemon starts at port 587 that acts as a
Message Submission Agent (MSA).
- ClientPortOptions=field1=value,field2=value,...
This option is similar to
DaemonPortOptions
but meant for outgoing
connections. See
DaemonPortOptions
above for the option values available.
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