Data::Throttler helps solving throttling tasks like "allow a single IP
only to send 100 emails per hour".

It provides an optionally persistent data store to keep track of
what happened before and offers a simple yes/no interface to an application,
which can then focus on performing the actual task (like sending email)
or suppressing/postponing it.

WWW: https://metacpan.org/release/Data-Throttler