If the current rate (as stored in this ${client_rate} macro) exceeds the limit imposed
inside the access database, the new connection is rejected with the following error:
433 4.3.0 Connection rate limit exceeded.
If you are interested in knowing the total rate of connections for all clients, see the
${total_rate} macro (?§21.9.95 on page 847).
21.9.25 ${client_resolve}
Result of lookup of ${client_name} V8.10 and later
When sendmail first assigns a value to the ${client_name} macro (?§21.9.21 on page 812) it
also looks up the hostname of that connecting client with DNS. Table 21-9 shows the
possible results of that lookup.
* Unless the -t command-line argument is used with makemap to change the separator.
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21.9 Alphabetized sendmail Macros | 815
The ${client_resolve} macro is useful in the Local_check_rcpt (?§7.1.3 on page 257),
Local_check_mail (?§7.1.2 on page 255), and Local_check_relay (?§7.1.1 on page 252) rule
sets. It can, for example, be used to accept mail only from machines whose hostname can
be successfully looked up with DNS:
LOCAL_RULESETS
SLocal_check_mail
R$* $: $&{client_resolve}
ROK $@ Okay
RTEMP $#error $@ 4.7.1 $: "450 Can't resolve hostname just now."
R$* $#error $@ 5.7.1 $: "550 Sending hostname must resolve!"
Here, the first rule transfers the value of ${client_resolve} into the workspace.
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