AllowBogusHELO

Allow no hostname with HELO or EHLO.

ColonOkInAddr

Allow colons in addresses. 

ConnectionRateThrottle

Slow the acceptance rate of new connections. 

DefaultCharSet

Define default character set. 

DialDelay

Set delay time for second connect() attempt.

DontBlameSendmail

Disable parts of security checking. 

DontExpandCnames

Prevent canonical name expansion. 

DontInitGroups

Do not use initgroups().

DontProbeInterfaces

Disable automatic probing of interfaces. 

DoubleBounceAddress

Set email address for error notifications. 

EightBitMode

Specify how to handle unlabeled 8-bit data. 

ErrorHeader (E)

Append custom text ahead of error message text. 

ForwardPath (J)

Set alternative locations of the .forward file.

HostsFile

Specify an alternative location for the /etc/hosts file.

HostStatusDirectory

Set the location of the directory containing persistent host status data. 

MaxDaemonChildren

Limit the number of forked children of sendmail.

MaxMessageSize

Set the maximum messages size. 

MaxMimeHeaderLength

Set the maximum length of certain MIME header field values. 

MaxRecipientsPerMessage

Set the maximum number of message recipients. 

MaxQueueRunSize

Set the number of queued messages that can be processed in one run. 

MinQueueAge

Determine the minimum amount of time a message must be in the queue before processing. 

MustQuoteChars

Set the list of characters that must be quoted in nonaddress information. 

NoRecipientAction

Determine how to handle headers without recipients. 

OperatorChars or $o

Establishe the list of separation operators. 

QueueSortOrder

Specify how to sort the queue. 

RunAsUser

Run sendmail as a non-root user.

SafeFileEnvironment

Select the directory for safe file writes. 

ServiceSwitchFile

Specify the location of the switch file for name services. 

SingleLineFromHeader

Convert all newlines in the From: header to space characters.

SingleThreadDelivery

Select single threaded delivery. 

UnsafeGroupWrites

Check for unsafe group permissions.