MAXRCPTCOUNT
From Qmail-LDAP Wiki
Maxrcptcount is the maximum number of RCPT TOs you accept before permanently rejecting this delivery attempt.
Default:
0 (which means no unlimited)
Affects:
qmail-smtpd
Example:
5
Note:
- This is a hard limit.
- If you just want to give some pain for smaller recipient numbers consider tarpit use as well.
