Normally,
sendmail limits the number of outbound RCPT TO:
commands allowed per session to the size of the DEFAULT_MAX_RCPT
compile-time macro (MAX...), which is defined
as 100 in sendmail/conf.c. When delivering an
envelope, sendmail will deliver only the maximum
number of recipients on the first try. Any that are left over will be
deferred until a later delivery attempt (usually during the same
queue run).
One problem with piling many recipients into a single envelope is
that some sites on the Internet refuse to accept mail when the
envelope contains too many recipients. Another, but opposite, problem
is that some sites can accept more than 100 recipients per envelope,
and you would prefer to send them as many as they can handle in a
single transaction.
One way to limit or expand the number of recipients allowed in an
envelope is to use this r= delivery agent equate:
r=val
If val is set to a non-zero value, it
changes the limit on the number of recipients allowed to the value
specified. If val is less than
or equal to zero, the limit is set to the value of the
DEFAULT_MAX_RCPT compile-time macro (MAX...).
Some delivery agents provide mc macros with
which to add an r= equate. For example, the
following mc configuration lines add that
default to the various smtp delivery agents:
define(`SMTP_MAILER_MAXRCPTS', `80')
this must be
MAILER(`smtp') before this
See the section describing a particular delivery agent to find an
appropriate mc macro with which to redefine the
r= for that delivery agent. See Table 20-1, in Section 20.4, for a guide
to all delivery agents.
For some delivery agents, there are no mc
configuration macros available to directly give a value to this
r= equate. Instead, you can use a bit of sleight
of hand to add an r= to a particular delivery
agent:
define(`LOCAL_MAILER_PATH', `/usr/lib/mail.local, r=200') this must be
MAILER(`local') before this
The LOCAL_MAILER_PATH mc configuration macro
(See this section) is usually used to define the path for
the local delivery agent. Instead of using it for
that reason, here we simply restate the path that appears in the
current sendmail.cf file, and add the
r= declaration to that path. As with all
modifications of delivery agent equates, the modification must
precede the MAILER declaration for the corresponding delivery agent.
