sendmail, 4th Edition

${nrcpts}

Number of envelope recipients V8.9 and later

The recipients of an email message can be specified or added to the message in several ways:

• Recipients can be specified as part of sendmail’s command line (List of Recipient Addresses on page 226).

• Recipients can be specified in message headers if a -t command-line argument is used with sendmail (-t on page 248).

• Recipients can be specified with the RCPT To: command (MaxRecipientsPerMessage on page 1050).

• Recipients can be added using aliasing (The aliases(5) File on page 460), mailing lists (Internal Mailing Lists on page 485), and expansion of users’ ~/.forward files (The User’s ~/.forward File on page 500).

• The MILTER interface (Create Milter Support on page 1170) can add and remove recipients as a result of policy decisions.

As each recipient is added to the internal list of recipients, sendmail updates the ${nrcpts} macro to reflect the current count.

The ${nrcpts} macro can be useful in the check_compat rule set (The check_compat Rule Set on page 259) which is called just before delivery. The value in ${nrcpts} can be used to check the number of recipients, and to possibly refuse delivery if there are too many recipients. (See also the MaxRecipientsPerMessage option, MaxRecipientsPerMessage on page 1050.)

${nrcpts} is transient. If it is defined in the configuration file or in the command line, that definition can be ignored by sendmail. Note that a $& prefix is necessary when you reference this macro in rules (that is, use