Events are logged, printed, and entered all in the same manner. There are thee types of events: two-letter, three-letter, and the Message-Id: header. Each has it own rules.

Two-letter Events

er=value	specifies ENVELOPE recipients, where the value is a combined good and bad recipient count.
hr=value	specifies HEADER recipients, where the value is the total of all To:, Cc:, and Bcc: recipients.
ho=value	specifies HONEY POT recipients, where the value is the total count of honey-pot recipients. (Also see HoneyFile in the configuration file.)
br=value	specifies BAD ENVELOPE recipients, where the value is the count of bad recipients. (Note that you must patch sendmail if you are running V8.12, for this count to work.)

Three-Letter Events

Three-letter event names specify boolean values. If present, they mean TRUE, and if absent they mean FALSE. Boolean expressions stand, or are specified, alone (no equal sign).

hed	boolean, where TRUE (present) means there were too many HEADER recipients. (Also see MaxHeaderRcpts in the configuration file.)
env	boolean, where TRUE (present) means there were too many ENVELOPE recipients. (Also see MaxRcptsPerEnvelope in the configuration file.)
hon	boolean, where TRUE (present) means there was at least one HONEY POT recipient. (Also see HoneyFile in the configuration file.)
mid	boolean, where TRUE (present) means there was a bad or missing Message-Id: header. (Also see CheckMessageId in the configuration file.)
frm	boolean, where TRUE (present) means there was a bad or missing From: header. (Also see CheckFromHeader in the configuration file.)
bho	boolean, where TRUE (present) means there was a bad ENVELOPE sender host. (Also see CheckSenderHost in the configuration file.)
rbl	boolean, where TRUE (present) means that the IP number was looked up at one or more RBL sites and found to be bad. (Also see RBLlist in the configuration file.)
abo	boolean, where TRUE (present) means sendmail, or an earlier Milter, rejected the envelope or connection for this IP number. (Also see MilterAbort in the configuration file.)
pip	boolean, where TRUE (present) means that the sending site attempted to pipeline before acceptance of pipelining was announced by sendmail. (Also see AdvanceWrite in the configuration file, and patching sendmail.)
for	boolean, where TRUE (present) means that sendmail thought the the sending site's hostname/IP-number combination was forged.
mmx	boolean, where TRUE (present) means that this envelope was received from one of our MX servers. (Also see LookBackOne and LocalHostName in the configuration file.)
net	boolean, where TRUE (present) means the message was received on a non-AF_INET network interface, such as the loopback interface.
aip	boolean, where TRUE (present) means this record's IP number is an alias for another IP number (Also see AddIPAliases in the configuration file.)

The Message-Id: Header

The Messsage-Id: header's value is specified by a msgid keyword. Because the Messsage-Id: header's value is enclosed in angle-braces, you should always quote this value. For example:

msgid="<foo@bar.com>"
When this event is logged or printed, the quotation marks will be omitted. If no Messsage-Id: header was present in the message, this event will print and log as:

msgid=